Atlas of leiden by Jesse

Jesse Dobbelsteen 4385055 AR1U090 R&D Studio l Q1 Analysis and Design of Urban Form Tutor: Els Bet 04-11-2016

TABLE OF CONTENT Introduction 4 Introduction History

Landscape 10 What is landscape? Landscape of Leiden Conclusion

Morphology 24 What is morphology? Morphology of Leiden Conclusion

The open city 36 What is the open city? Conclusion

Complex systems 44 What are complex systems? Conclusion

Conclusions 52 Layers

Underlying structure SWOT Brain city Green connection Water city

Apendix 68

INTRODUCTION

Haarlem

Amsterdam

Randstad

Leiden Utrecht

Den Haag Delft

Arnhem Rotterdam

INTRODUCTION This atlas contains a series of maps, principles and photoâ&#x20AC;&#x2122;s as a way to analyse the city of Leiden. The analysis is structured in four main topics: Landscape, morphology, the open city and complex systems. Each analysis tries to answer the main question: What influence did this have on the spatial form and structure of Leiden? To understand the city there has been looked at different scales, layers and time periods. The main tool used for the analysis is mapping. At the end of the atlas there will be a future vision of Leiden and a city portrait which shows the image of the city as I see it. Leiden has an interesting position in the Netherlands. It is part of the Randstad which contains seven major cities. The city is situated at a central position in the Randstad which makes it a prominent city in this system of urbanization. Leiden is known for housing the oldest university of The Netherlands dating back from 1575. The city has a population of approximately 122,500 residents.

< Position of Leiden in The Netherlands

200

1200

1700

Small settlements aside of the river Rhine.

Development of the city

Three different cores develop on the crossing of the Rhine, on an artificial hill a stronghold is built. Peat reclamation structures formed the landscape around the city

First real flourishing period of the city followed by the golden ages till the early 17th century. Previous peat reclamation structures decided the structure of the city centre.

HISTORY 1900

2000

2016

Stagnation on the city development because of the collapse of the textile industries. The population shrunk and the city fell in decay.

City starts to flourish again because of the textile industry and the university. University industries start to develop. New developments around the singels of the city centre occur. Forming a second ring around the city centre.

Explosive developments between the two world wars for housing the middle class. New building concepts are being applied such as closed building block and the cauliflower concept.

LANDSCAPE INFLUENCE OF THE LANDSCAPE ON THE CITY

LANDSCAPE AS NATURE

LANDSCAPE AS OPEN SPACE

LANDSCAPE What is landscape? An interesting question to ask an urbanist. At first you would say landscape is all the flora, nature and green you see around you. From this view there is clearly a distinction between cities (red) and landscape (green). But another way to look at landscape is that is contains all the open space. In a way it flows through cities to all the open spaces that are accessible. Therefore we not only have to look at the green spaces but also at the open spaces in the city. The main question for this chapter is what influence has the landscape on the form of the city?

LEGEND Young dune deposition Old dune deposition Young clay Young clay on peat Bog deposition Old clay Leiden Tidal deposition Peat Haarlem

Leiden 14 Den Haag

Map of the geology in the Holoceen

LANDSCAPE In the map on the left you can see Leiden with two other cities and the geological layer beneath them. Interesting to see is that Haarlem and Den Haag both formed on a sand ridge but Leiden in the debouchment of the river Rhine. This area is an area of clay deposits with a peat layer on top of it. The main reason for settling here was the option for peat reclamation and the close position to the sea and the river Rijn. Because of this position in the debouchment, Leiden has to cope with wet grounds and the drainage of water. In the series of maps on the right deforestation is shown around Leiden. You can see that a lot of forest disappeared to make room for peat reclamation. Peat reclamation structures had an important influence in the form of the city. The straight ditches formed the base structure of the city centre and later expansions.

N N

Peat reclamation structures from the start of the city

Deforestation of the area around Leiden

UNDERLYING LANDSCAPE This map shows the underlying structure of the landscape around the city centre in 1850. The peat reclamation structures are very dominant in the landscape as everything in that time revolved around the peat industry. These structures had a major impact on how the city is formed. The rigid lines formed the structure of streets and canals becoming the building blocks of the city. In the chapter about morphology it will become clear how much the impact was on the built environment.

< Map of the underlying landscape of Leiden

NATURE IN THE CITY After looking at the underlying landscape structures we take a look at the nature on top of it. On the left map there is an overview of all the green areas of the city. Here we can see that the green is really fragmented. The municipality of Leiden also made a map of the most important green areaâ&#x20AC;&#x2122;s and connections in the city. Noticeable is that the green is mostly annular and provide nature just for a certain zone or neighbourhood.

^ Map of the most prominent green areas (source: Municipality of Leiden) < Map of all the nature in the city

GREEN ISLANDS In this reduction of the green spaces we can clearly see how fragmented the green is. In the map is a distinction between the sport fields (light green) and parks (dark green). Every neighbourhood has its own green space, but is separated from the rest. In the city centre are almost no green spaces due to the historical growth of the city. When the city walls werenâ&#x20AC;&#x2122;t necessary anymore, the municipality decided to make a singel and develop parks next to it. If we reduce the image even more we get a plant cell with the vacuole as the heart of the centre and separated green spaces (chloroplast) around it. The plant cell purely represents the image of the nature in the city.

Schematic concept green spaces in Leiden 21 Cell kern

Chloroplast Cell wand Cellmembrame

LEGEND Parks Sport fields Water Legal border

< Clusters of nature

Vacuole

Plant cell (source: biowebsite.nl)

City centre (1800)

14.5

First expansion (1940) (Front and backside)

24.5

Cauliflower expansion (1980)

CITYSCAPE

First expansion (1940) As the city grows other ideas about how the city should look like are implemented on the cityscape of Leiden. We can clearly see that the sections become much wider and more green is implemented. The first one is the front of the buildings. Here we see every apartment has a green line in front of it with trees and a clear distinction between the sidewalk, parking space and main road. A lot more room is reserved for the car. The back side of the apartment is one big green area with trees and no room for cars.

A cityscape is the urban equivalent of a landscape. It represents the urban landscape flowing through the city. In these sections we take a closer look at how this cityscape functions in Leiden. In the previous paragraph we looked at the parks and nature in the city. Here we see the typical cityscape of three different expansions through time. Amount of green, width of the section and the amount of room for the car are the three main themes for the sections. City centre (1800) In the city centre we see two different road sections. The first is the smallest one of just 5 meters wide. The second one are the main roads/ open spaces of the centre. The small profile has no green but in the second profile, because of the limited space, they combined parking for the car with greenery and applied trees in the street. The first section has no room for cars, only to pass through. In the second one the car is more prominent

Cauliflower expansion (1980) The Cauliflower expansion has two different cityscapes. In the first section we see that the front of the house is facing the back of the other house. In this way you get a real closed street with very few interactions. There is a lot of green in the street, but half of it is hidden by the fence of the backyard. In the second section two fronts are facing each other in a very wide section. A lot of room is reserved for parking and movement of the car. The idea behind this is that you park your car in front of the house and go to your own green space in the backyard.

MORPHOLOGY GROWTH OF THE CITY

Leiden in 200

N Leiden in 2000

AGGLOMERATION In the chapter of landscape we saw that Leiden originated in the debouchment of the river Rijn. If we project the debouchment on the current agglomeration we see that the development of buildings follows this direction. The reason behind this is that most smaller settlements started next to the river Rijn and through time these settlements grew together. The result of this is a large development perpendicular to the sea in a east-west direction. Due to this development in the debouchment Leiden has to cope with a lot of water. On the map of Leiden in 2000 you can see that the polder structures have a prominent position in the area. They assimilate most of the water coming through the Rijn.

< Agglomeration on the high scale

1850 - 1910 First developments outside the city centre. Development of train track doesnâ&#x20AC;&#x2122;t have a big effect on the growth of the city

1910 - 1940 The first large scale expansion of Leiden after WW I. A high need of buildings resulted in a new typology of the closed building block. These new neighbourhoods were mostly for the middle working class. Areas around the train station starting to develop.

1940 - 1970 After WW II the need for dwellings increased resulting in another large expansion. Also the development of a new large campus of the same side of the city centre occurred on the other side of the train station.

1970 - 2009 Most recent expansion of Leiden. A new concept for dwellings was invented, called the cauliflower neighbourhood. Two of these neighbourhoods developed north and south-west of the city.

GROWTH OF LEIDEN On the left is a series of maps which show the most important expansions of the city. In the reduction maps below we can clearly see the expansions. Interesting is that in the beginning the city grew as the age lines of a tree but that later expansions had limited space for growth. Reasons for these limitations were the train tracks, canals and legal borders of the city. This results in the distortion of the age rings of Leiden and a north-west development of the city.

INFRASTRUCTURE An important influence on the form of the city are the infrastructural elements. They run like veins through the city connecting the building blocks together. There are three layers in Leiden that have the most impact. Those are: - Railway - Highway with the main connections - Streets Each layer has its own impact on the city. The railway forms a big barrier between the old city and the bio science park as it cuts the campus away from the rest of the city. The two highways north-west and south-east form a wall that prevents expansions in those directions. The last layer of veins connects the neighbourhoods to the main infrastructure. The network consists of three circles around the inner city and a number of lines from the inner city outwards in a radial form. Interesting to see is the street pattern and how it differs in every neighbourhood. In the city centre you clearly see the peat reclamation structures in the street patterns. But in the cauliflower expansions the underlying landscape structure is ignored.

LEGEND Main infrastructure Railway Sub infrastructure Water < Map of the infrastructure of Leiden

MORPHOLOGY Each expansion of Leiden came with its own ideology about how the city should look like and function. Through time there are four distinctive urban fabrics which formed the city. These four fabrics are the city centre, post-war expansion, cauliflower expansion and the bio science park. How do these fabrics work? What are their functions? How are they implemented? These questions will be awnsered in the next paragraph.

Merenwijk (1980)

Bio sciencepark (1980)

City centre (1800)

Burgemeesterswijk (1940)

Morphology

Merenwijk (1980)

Plots

Form & Function

Organic form

Single form Single function

Very large plots

Single form Multi function

Bio sciencepark (1980)

City centre (1800)

Small diverse plots Structured by rigid lines from polders

Multi form Multi function

Burgemeesterswijk (1940)

Small plots in clear system of islands

Single form Single function

MORPHOLOGICAL SYSTEM System

Explanation

Typical about the cauliflower expansions are the way the plots are set up. The plots are very natural and divers resulting in the distinctive form of the dwellings. The dwellings have one form with one function. Almost all dwellings have a small front yard and a larger backyard. Typical about the cauliflower neighbourhood of Leiden is its closed system. Everything is directed to the central ring road and the park. Because of this there is no option to expand this system any further as it is.

The university campus has a lot of open spaces with large plots. Everywhere on the campus this structure is implemented. Each plot mostly has only one large building on it. Each building on the campus has its own distinctive form and most of them have more than one function in the building. The campus has a pre-made structure of plots where new buildings can be built. So trough time the campus will become more dense.

The blocks in the city centre have a very rigid form because of the peat reclamation structures which results in strong lines. But the plots inside these blocks vary a lot in size. The buildings have multiple forms and functions. Typical for most buildings in the city centre is that the ground floor is a shop and above that are residential functions. The city centre has a very strong system of blocks where the content can change easily without changing the urban fabric of the city. The blocks are the same size but can have different content.

Typical about the post-war expansions is the idea of the closed city block. Every dwelling has the same qualities with a small front yard and a larger backyard. Every building has the same form and residential function. The system is easily extendable because of the form of the blocks. It is a stamp which you can duplicate as much as needed.

OPEN CITY THE DEMOCRATIC DOMAIN

Source: slowstreets

DEMOCRATIC SPACE What is democratic space? This is an interestion question because it can have a lot of different views on it. There are three different open spaces in the city. First of all there is the open space. This contains all the open space in the city, everything outside a building. The second kind of open space is the public space. Everything that is accesable to the public. So these don’t contain private spaces. The last one are the democratic spaces. These spaces allow a physical exchange between different social groups. There is room for interaction between people, animals and objects. The space is accessible to everyone. There is an option to stay or to move through the space. And maby the most important one is that it is a place where you can express your idea’s and opinions.

Room for interaction

Option to stay/sit and move trough

Accessible to everyone

Place to express idea’s & opinions

Cauliflower

City centre

Campus

Open space in the urban fabric

Post-war

LEGEND Nature Square Water Democratic space Main movement Secundary movement

HARD VS SOFT Leiden has a lot of different open spaces each with its own function and purpose. In this analysis four different areas in Leiden have been unraveld in the hard and the soft open spaces. Hard open spaces are the squares and parking lots. The soft open spaces are the parks and green spaces of the neighbourhood. These open spaces were tested to the principles of the democratic space to see how much democratic space is there in the neighbourhood. The main movement is shown with the sub movement between it. There are three ways an open space is intergrated in the urban fabric as shown in the principles on the left page. You can pass through the space, along the space and the space can be the end of the movement. The cauliflower neighbourhood has two different faces of open spaces. One has a lot of green and is easaly accessible to everyone, resulting in a democratic space. The other face is more a structure of hidden squares and green places, making it less to no democratic space. There is one main movement connecting these two faces together. The city centre has a very clear main movement between the train station and the city centre. It passes along and through different democratic spaces, mostly squares. The democratic space in the middle opens the route towards the centre, directing the visitor in that way.

The post-war neighbourhood has a main movement towards the park on the far east. Right when you enter the area the route splits up and forms non-democratic spaces between the route. These open spaces feel like they belong to the residents in that neighbourhood and therefore are no democratic spaces. The campus has a very different structure than the other areas because of its open design. There are a lot of open spaces, mostly green, but only a few of them are accessible to everyone. There is very little interaction between visitors in the open spaces, only around the train station and the park north of the campus. The cause of this is probably because of the large buildings with their own systems of open spaces inside them. Outside the buildings the space is used to move through instead of staying. The image below shows all the open space in the city. These include the open, public and democratic spaces. You can see as the the city grows more open spaces are implemented in the city fabric resulting in a more open character.

< Map of all the open space in Leiden

Neighbourhoods

City centre

1.1

2.1

3.1

OPEN SPACE

second one is a more secluded open space with an element in the middle to make two different spaces in one. One space is to move through and the other to stay and sit. In the third one the church in the middle is the main actor of the square. From every direction the church is visible. To understand the open spaces more we take a closer look to six differ- To indicate the entrance of the church more open space has been made ent spaces. Three of them are from neighbourhoods and three from the in front of the church. old city. The first of the neighbourhoods is a very private secluded open space. Therefore it doesnâ&#x20AC;&#x2122;t function like a democratic space but more as a space for the residents of that area. The second one is also very secluded, but it has a route that links the different open spaces together therefore becoming more accessible for other people. The third is the most democratic of all. A lot of open space is shared with many different people. The apartment blocks contribute to this diversity of people with different backgrounds and ages.

1.1

All of the squares shown of the city centre are democratic spaces because they are accessible, give room to interact and you can stay or move through them. They mostly differ in the way they are implemented in the urban fabric. The first functions as way to direct the visitor in a certain direction because of the form and direction of the open space. The

43 2

2.1

3.1

COMPLEX SYSTEMS LAYERED CITY

COMPLEX SYSTEM A city consists of many different complex layers wich are all connected to eachother. In the previous chapters we covered some of these layers to get a clear image of the city and the influence of the underlying landscape on the form of the city. These complex systems are devided in three main layers: - Occupation - Networks - Substratom Each layer has its own systems but are connected to the other layers as the image on the left shows. Together they form the complexity of the city.

If you look at the services in the city centre you see that most of them are clustered together. The shops are mostly situated along the river and on the route towards the train station. The educational services are mostly situated south-west of the city centre on the old university campus of Leiden. The offices are a bit more dispersed but most of them are around the train station and east of the centre.

The cauliflower neighbourhood Merenwijk is very limited in services. There are three small clusters of educational buildings and only one with shops. This applies to the idea that there is one centre where all the residents do their shopping. There are almost no offices in the neighbourhood, but the ones that are there are also clustered around the shopping centre. 48

On the campus there is a clear dichotomy between educational and office functions. The north part of the campus is mostly for educational purposes and the south for the offices. There are no shops on the campus, so people have to go to other places for shopping or leisure.

LEGEND Educational Office Shops

SERVICES A city contains a lot of different services which provide diversity, interaction and movement. They are part of the complex system occupation and are the top layer of the city. In the series of maps on the left three main services have been looked at in the urban fabric:

The campus will also feel less lively because of the lack of shops and the clear dichotomy between educational and office functions. A result is that the campus is only visited by the users of the buildings and not by other visitors.

- Shops - Offices - Education

We can conclude that the city centre is more lively because of the diversity of services and uses. But how does it work on the smaller scale? To answer that question we take a closer look at the services in the city centre combined with the public spaces shown in the image below. You can see that the shops follow the main route through the city that connects the points of interest in that area. But if you go off the main trail youâ&#x20AC;&#x2122;ll get to a much more quiet place in the city with less services. So to be part of the liveliness a visitor has to stay on the main routes of the city.

If you compare the three systems of services you can see that the city centre has the most services to offer. Merenwijk has the least services and is mostly residential. The campus only have offices and educational services and almost no residential housing. These different collection of services result in different ways a neighbourhood is perceived. The city centre will always feel lively and active because there are so many services. Whereas Merenwijk will feel more desolated and quiet. The services here are only meant for the residents of the neighbourhood so external people will not visit this place.

Age 0-14

Age 15-24

Age 45-64

Non-western immigrants

Moroccans

Turkish

Average income

Average housing price

Most common worksector

POPULATION An important complex system of the layer occupation is the population of Leiden. This can say a lot about how the city functions and why different neighbourhoods are more pleasant than others. If we look at the ages of the population we see an interesting shift of where they live. The ages between 0 and 14 years old live mostly on the outskirts of Leiden. But if we look at where people between 15 and 24 years live we see that they move to the city centre. A cause of this is that a main industry of Leiden is the university, resulting in a lot of students move into the city centre. After that period residents again move to the outskirts of the city where the neighbourhoods are more quiet.

In the maps of non-western immigrants we can see that there are a few clusters of where they live. Mostly on transition areas between neighbourhoods with a high income. Immigrants first arrive at a poor neighbourhood and if they have enough money they move to a richer part of the city. In this way the poor areas stay poor instead of giving the neighbourhood a boost. If you compare the average income with the average housing price they almost completely match. This confirms the conclusion that people who earn more will move to a richer neighbourhood.

Most of the city consist of the commercial sector covering trade and finances. The south part of the city and most northern part consists of non-commercial services like public administration, defence, education, health care, public order, etc.

LEGEND non-commercial services Commercial sector Agriculture

CONCLUSIONS THE FRAGMENTED CITY

Form Occupation

Functions Population

Bariers Networks

Connections

Fragmented Substratum

Cityscape

Base structure Substratum

Identity Connector

LAYERS The complex system of Leiden consists of a multilayered system of substratum, networks and occupation. The oldest and most resilient layer is the water layer. This forms the base structure and identity of the city. It also connects most of the city parts together. The layer on top of it is the landscape layer. The fragmented nature cores and the cityscape are part of this layer. This layer can change on an average way because it is less imbedded than the water layer. On top of that is the network layer. The infrastructure ensures connection to othere parts and places but also causes bariers between neighbourhoods resulting in the fragments. This layer can change fast through time. The last layer is the layer of occupation concerning the form with their functions and the population of the city. This layer is the most subject to change.Together these layers form the city as it and how it functions.

UNDERLYING STRUCTURE By looking at the elements from the previous paragraph and link them to the current urban form, we can see what the influence of these elements was on the city. It first started with the most prominent structure of the river Rijn. This structure is still present in the current city form. The structure shapes the city centre. A second structure that is clearly seen in the city centre and the surrounding neighbourhoods are the peat reclamation structures. The rigid lines of these ditches formed the streets, canals and city blocks. The third main structure is the railway on the west side of the city. The railway forms a barrier for development and cuts through the urban fabric. Because of this structure a large part of the city gets disconnected. A fourth structure is the canal east of the city formed in 1950. The canal has the same impact on the city fabric as the railway as it cuts through. The canal has a large impact on the form of the city blocks. Just as the railway the canal creates a disconnection between the different neighbourhoods. The fifth and most recent structures are those of the two highways north-west and south-east of the city. Because of these barriers the city has to adapt its development to these structures and grow north and south.

There are roughly three categories of structures: 1. The dynamics of the delta; these are the rivers, creek ridges and levees 2. Peat reclamation structures; Highly distorted system of lots, ditches and roads. 3. The traffic machine; The newest layer on top consisting of highways, railways and roads. In the past urban developments respected the underlying structures and formed the city to these structures. But later additions did not respect the original landscape, this resulted in a city of separated islands. These islands have their own internal logic and are sometimes poorly connected on a higher scale level. The question arises in which direction should the development of the city go? Should these neighbourhoods be connected or disconnected? Both directions could have their benefits, but also their weaknesses. 57

PORTRAIT In the conclusions of the atlas came forward that Leiden is a fragmented city but with a very strong city centre. The city has a circular growth with a small distortion to the north and south. In the portrait I show Leiden as a fragmented city but because the city centre is the most resilient form it is still a whole. Water is the strongest structure as it is flowing through the cracks. This is the force that connects all the fragments together. The urban form fades as there is no respect for the underlying structure which makes them less resilient to future developments. This becomes more clearly in the model. By adding water as the underlying structure you can see that through time some structures remain and others dissolve because they didnâ&#x20AC;&#x2122;t respect the base structure, the water.

SWOT ANALYSIS Strenghts

Weaknesses

Leiden has a lot of green spaces that can be connected with the right developments.

The fragmented state of the city is the largest weakness of Leiden.

The city hearth is has a lot of potential to be the centre to these connections.

The poor connection between the bio science park and the city centre causes the dislocation of the campus. Disrespect for the underlying landscape in certain neighbourhoods causing them to be less resilient to change.

Opportunities

Threats

To make the hearth of the city even stronger the city centre can develop a green ring around the centre connecting all the parks together.

The railway stays a large barrier between different parts of the city.

Old industrial buildings can be re-used for a museum or event location. West of the city centre the small industries can be moved to make room for more residential areas with a harbour entrance to the city. East of the city next to the railway there is room for student housing. They will be close to the old university campus and to the city centre. A better connection through the train station between the bio science park and the city centre. The green space between Merenwijk and the city centre has potential for development and creating a green connection.

The lack of diversity on the campus in functions make the place less attractive for visitors.

BRAIN CITY You can see the relationship between the bio science park and the old city centre as a human brain. The campus as the left brain and the historical city centre as the right brain. But between those two halves there needs to be a good connection. Right now the central station with the railway forms a great barrier between those two halves. Therefore this area needs to develop towards better accessibility. And to make the bio science park flourish again different functions are added in the park. The result will be a much more divers and vibrant left side. By introducing a knowledge backbone from the bio science park towards the old university the connection with the old city centre will be strengthened.

GREEN CONNECTION The connection between Merenwijk and the city centre is very weak. Because of the fragmented city Merenwijk feels like a separated island in Leiden. By giving the in-between space an green impulse with green connectors the relation with Merenwijk can be restored. These connectors will finish at a park of the green ring of the city centre. In this way everything will be linked together in a circular and perpendicular structure to the city centre. Each green route will finish at a larger park in the neighbourhoods around the city.

WATER CITY The most prominent structure in Leiden is the water. It flows through the city as veins connecting every fragment together. But these structures can be strengthened. Surrounding neighbourhoods will be connected through different waterways leading towards the city centre. To make these routes more interesting point of interest are added at key points. Each neighbourhood will have its own special point of interest representing their identity. Alongside the waterways there is room for cyclists and pedestrians. In that way you donâ&#x20AC;&#x2122;t need a boat to be part of the network and visit these points of interest. In the city centre is the heart of this network. Here people can enjoy and experience Leiden from the water and alongside it. Everything together will form a structure which give Leiden the identity as water city.

APENDIX Sources: Books: Colenbrander, B., & Bazelmans, J. (2005). Limes Atlas. Rotterdam: Uitg. 010. Habraken, N.J., 2016. Cultivating Complexity: The Need for a Shift in Cognition. In Complexity, Cognition, Urban Planning and Design (pp. 5574). Springer International Publishing. Moudon, A.V., 1994. Getting to know the built landscape: typomorphology. Ordering space: types in architecture and design, pp.289-311. Palmboom, F., 2010. Drawing the Groundâ&#x20AC;&#x201C;Landscape Urbanism Today: The Work of Palmbout Urban Landscapes. Walter de Gruyter. Rutte, R., Abrahamse, J. E., & Diesfeldt, O. (2014). Atlas van de verstedelijking in Nederland: 1000 jaar ruimtelijke ontwikkeling. Sites: Geo info: http://pdokviewer.pdok.nl/ Geo info: http://kaart.edugis.nl/ Heightmaps: http://ahn.arcgisonline.nl/ahnviewer/ History: https://www.erfgoedleiden.nl/ Maps: http://www.openstreetmap.org/ Plant cell: http://biowebsite.ilbiondino.nl/ Satelite photos: https://www.google.nl/maps/ Images: 68 Central station: http://onsoudleiden.nl/winkel/niet-gecategoriseerd/centraal-station/ Democratic space: https://slowstreets.wordpress.com/2015/04/27/lessons-from-copenhagen-key-ingredients-for-a-successful-public-space/ Leiden university: https://www.kb.nl/themas/filosofie/willem-jacob-s-gravesande/s-gravesande-in-de-dynamische-wereld Leiden slums: http://www.hleun.nl/leiden%20vroeger%204/ Painting zicht op leiden: http://www.schilderijen.nu/schilderij/jan-van-goyen/gezicht-op-leiden-uit-het-noordoosten?i=10837 Peat reclamation: http://www.itulip.com/forums/showthread.php/20698-A-model-for-how-things-will-go-with-Peak-Cheap-Oil-Or-Peak-Peat Settlement: http://www.stichtinghistorischezitmuren.nl/vlaardingen.html Stronghold: http://www.verzamelaars.net/veilingvinden/december2014/Leiden-C.-Pronk-J.C.-Philips-De-Burgt-te-Leiden-1742-644772.html Textile factory Leiden: http://www.hollebeek.nl/leiden/fabrieken/ldnfabt.html