Martello tower

Circular tower for coastal defence. Formerly much used in Europe, many were built along the English coast, especially in Sussex and Kent, in 1804, as a defence against the threatened French invasion. The name is derived from a tower on Cape Mortella, Corsica, which was captured by the British with great difficulty in 1794, and was taken as a model. They are round towers of solid masonry, sometimes moated, with a flat roof for mounted guns.