Dartmouth Castle is built on a rocky promontory at the narrowest part of the entrance to the Dart estuary, designed to protect the harbour at Dartmouth from attack by foreign vessels. A small fort was built in 1388 to protect expensive stone-throwing machines whose range just about covered the narrow harbour entrance. Between 1481 - 1495 a new tower was constructed to mount heavy guns, the first purpose-built artillery tower in the country. Over the following centuries, as the power and range of guns improved, other gun emplacements were added to the castle in positions that allowed them to fire on ships well before they reached the narrow harbour entrance. By the 19th century, Dartmouth's importance as a harbour had declined and the defences at the castle were reduced, although not entirely abandoned. The last gun emplacements to be built and manned were added during the Second World War.