Her Majesty's Naval Base, Clyde (HMNB Clyde; also HMS Neptune) primarily sited at Faslane is one of three operating bases in the United Kingdom for the Royal Navy (the others being HMNB Devonport and HMNB Portsmouth). It is the service's headquarters in Scotland and is best known as the home of Britain's nuclear weapons, in the form of nuclear submarines armed with Trident missiles.