An archaeological watching brief was carried out on excavation and installation of a new drain around the foundations of St Peter’s Church, Old Cogan, Vale of Glamorgan (centred NGR ST 316875 170568). The main aim of the work was to reduce the ingress of damp which has been caused by the build-up of ground) on the north and east sides of the church. An existing medieval drain was exposed and recorded during the excavation and a number of archaeological finds, specifically pottery and iron objects were recovered.