The Device Forts, also known as Henrician castles and blockhouses, were a series of artillery fortifications built to defend the coast of England and Wales by Henry VIII.
[4] Armed with artillery, the forts were intended to be used against enemy ships before they could land forces or attack vessels lying in harbour.
[5] The castles were commanded by captains appointed by the Crown, overseeing small garrisons of professional gunners and soldiers, who would be supplemented by local militia in an emergency.
[11] By 1900, however, developments in guns and armour had made most of the Device Forts that remained in service simply too small to be practical in modern coastal defence.
[13] Coastal erosion over the centuries had extensively damaged or completely destroyed some sites, but others have been restored and opened to the public as tourist attractions.