Margaret Clap (better known as Mother Clap, died circa 1726) was a woman who ran a brothel for homosexual men in London in the early part of the 18th century. At the time homosexuality in England was illegal, punishable by execution. Despite this, particularly in larger cities, private homosexual activity did take place. To service these actions, mainly in the cities, there existed brothels where men (from all social classes) could find homosexual partners. These were called molly houses, and the most famous of these was Mother Clap's molly house in the Holborn area of London, specifically on Field Lane (heading north to Farringdon). It was later destroyed by the construction of Holborn Viaduct.