Sandgate Castle

Sandgate Castle is an artillery fort originally constructed by Henry VIII in Sandgate in Kent, between 1539 and 1540. It formed part of the King's Device programme to protect against invasion from France and the Holy Roman Empire, and defended vulnerable point along the coast. It comprised a central stone keep, with three towers and a gatehouse. It could hold four tiers of artillery, and was fitted with a total of 142 firing points for cannon and handguns.

• http://en.wikipedia.org/wiki/Sandgate Castle