|The Principality of Sealand is a micronation that claims as its territory Roughs Tower as well as territorial waters in a twelve nautical mile radius. Roughs Tower is a former Maunsell Sea Fort located in the North Sea 10 km off the coast of Essex, UK.|
HM Fort Roughs was constructed by the UK during World War II in 1942.
It is comprised of a floating pontoon base with a superstructure of two hollow towers joined by a deck . The location chosen was in international waters, outside the then three-mile territorial water claim of the UK.