The New Ambassadors Theatre was designed by WGR Sprague, and is one of the smaller West End venues. The 444 capacity venue was completed in 1913, and up until 1999 was known as The Ambassadors Theatre. The theatre features a very shallow, proscenium arched stage and is designed for small revues or plays. The most notable production at the theatre, like its companion theatre of St Martin’s, is the long run of The Mousetrap, which began here in 1952 and moved to St Martin’s in 1974.