Three large coastal artillery forts known as redoubts were built between 1804 and 1812, at Harwich, Dymchurch and Eastbourne. They provided extra troops to support the chain of Martello towers along the East Sussex and Suffolk.
The redoubts are circular, brick built structures up to around 68m in diameter, and stand to a height of around 12m. They comprise 24 casemates built around a central, circular parade ground. These blast proof casements provided living quarters and services for the troops. On top of casemates was an open gun platform with emplacements for ten 24- pounder cannons, each with its own adjacent magazine, for ammunition. The fort at Dymchurch was much added to in WW2 ( these modern square brick additions can be seen in my pictures) It remains on the edge of MOD land and is not open to the public as it is within a live fire zone.