Dymchurch Redoubt was constructed between 1804 and 1812 as part of a general building plan that included Harwich Redoubt and Eastbourne Redoubt. Dymchurch Redoubt was built to support a line of twenty one Martello Towers, that ran along the south coast from Hythe in Kent to Rye in Sussex.
As with Harwich and Eastbourne Redoubts, Dymchurch Redoubt has a brick circular keep on two levels. The works are sunk into the ground, with a dry ditch around the outside. There are no caponiers covering the ditch.
The outer wall had ten embrasures for 24-pdr smooth bore guns mounted on traversing carriages and firing through granite faced embrasures. The old 24-pdrs were replaced with two 68-pdr RMLs and ten 32-pdr in about 1871. In 1895 when three additional 68-pdr were mounted, probably replacing the old 32-pdrs facing the sea.
During World War 2 and Emergency 6-inch battery was constructed on the Redoubt, and various pillboxes built to cover the beach and land approaches. These new works were largely built over the old gun positions.