Sandsfoot Castle is one of Henry VIII's Device Forts, also known as Henrician Castles, built around 1541 to the west of Weymouth, Dorset, England, opposite its contemporary Portland Castle. Together these two forts put the whole of Portland harbour and the roads within range of their artillery, thus protecting shipping from foreign raiders, and preventing an invading landing force from forming up offshore, although the castle was always vulnerable to attack from a landward direction.