Sandsfoot Castle, also known historically as Weymouth Castle, is an artillery fort constructed by Henry VIII near Weymouth, Dorset. It formed part of the King's Device programme to protect against invasion from France and the Holy Roman Empire, and defended the Weymouth Bay anchorage. The stone castle had an octagonal gun platform, linked to a residential blockhouse, and was completed by 1542 at a cost of £3,887. Earthwork defences were built around the landward side of the castle, probably in 1623. Sandsfoot saw service during the English Civil War, when it was held by Parliament and Royalists in turn during the conflict. It survived the interregnum but, following Charles II's restoration to the throne, the fortress was withdrawn from military use in 1665.