The roof space of St Thomas's Church (1703) in Southwark was utilised as an operating theatre for St Thomas's Hospital from 1821 to1862. In the form of a semi-circular amphitheatre, it is the oldest room of this type in London. Today it is incorporated into a museum illustrating the history of 19C surgery. The chapel is now used as a chapterhouse for the cathedral canons. One wing of the old buildings now houses a post office.