Hoo FortChatham, UK
Hoo Fort is built on a small island in the middle of the River Medway, about one and a half miles downstream from the main Chatham Dockyard, and one mile from Fort Darnet. Construction of the Fort commenced in 1861 but it was not completed for ten years, with constant problems of subsidence and damp. A circular fort with eleven 9-inch RML guns facing in all directions. Originally intended to be three storey structures, they amended this two two. The lower level was the magazines and accommodation, while the upper level had the gun emplacements.