Interiorization of space has dramatically challenged the conceptual understanding of city and architecture. Examining the phenomenon in Galleria in Milano and the Venetian Casino in Macau, the fundamental distinction between interior and exterior has to be redefined. Building facade is no longer being read as the external envelope and user’s perception on an architecture is no longer from the outside formal expression. This paradigm shift changes the way we read and theorized interior and exterior in the discourse of architecture.