A Lock Hospital was a hospital that specialised in treating venereal diseases. They operated in Britain and its colonies and territories from the 18th century to the 20th. The military had a close association with a number of the hospitals. By the mid 19th century most of the larger army bases in India were home to a lock hospital.[1] In 1858 the Admiralty paid to have one opened in Portsmouth and in 1863 another in Plymouth.[2]