St. Martin's Theatre - Designed in 1916 by W G R Sprague the early years of the theatre were given over to contemporary dramas dealing with such diverse subjects as venereal disease, homosexuality, divorce, alcoholism and insanity. Interspersed with these were productions of a lighter nature in the guise of comedies and musicals. As a sign of things to come the thriller Sleuth opened in 1970 and ran for three years giving way to Agatha Christie's The Mousetrap, the world's longest running 'whodunit', which transferred here from the Ambassadors located next door.