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 England 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.

Sandgate was taken by Parliament in 1642 at the start of the first English Civil War, and was seized by Royalist rebels in the second civil war of 1648. The castle was extensively redesigned between 1805 and 1808 during the Napoleonic Wars. The height of the castle was significantly reduced and the keep was turned into a Martello tower; when the work was completed, it was armed with ten 24-pounder guns and could hold a garrison of 40 men.