A turnstile, also called a baffle gate, is a form of gate which allows one person to pass at a time. It can also be made so as to enforce one-way traffic of people, and in addition, it can restrict passage only to people who insert a coin, a ticket, a pass, or similar. Thus a turnstile can be used in the case of paid access (sometimes called a faregate when used for this purpose), for example public transport as a ticket barrier or a pay toilet, or to restrict access to authorized people, for example in the lobby of an office building.

The Central Government War Headquarters is a complex built underground as the United Kingdom's Emergency Government War Headquarters – the hub of the country's alternative seat of power outside London during a nuclear war or conflict with the Soviet Union. It is located in Corsham, Wiltshire, in an old underground Bath Stone quarry known as Spring Quarry.