Camber Castle

Camber Castle, also known formerly as Winchelsea Castle, is a 16th-century Device Fort, built near Rye by King Henry VIII to protect the Sussex coast of England against French attack. The first fortification on the site was a small, round artillery tower, constructed by Henry between 1512 and 1514, overlooking the Camber anchorage and the entrance to Rye Harbour. In 1539, increasing tensions with France encouraged Henry to rethink his coastal defence plans, and Camber Castle was rebuilt and extended over the next year under the direction of the Moravian engineer, Stefan von Haschenperg. The results were considered unsatisfactory and further work was carried out from 1542 to 1543, at great expense, to rectify the problems. The result was a large, concentric artillery fort, with a central keep, surrounded by four circular bastions and a circular entrance bastion, built from stone and brick.

Source: Wikipedia