Maunsell Forts, the United Kingdom

During the Second World War, three anti-aircraft forts were built in 1942 as an advance line of defense to protect the important shipping line from enemy ships and aircraft, And to protect the Thames Estuary or as to counter attack enemy planes that were relying on the safety of the Thames estuary and to help defend the United Kingdom in general.

These anti-aircraft tower-forts were constructed with each fort consisting of a cluster of seven stilted buildings surrounding a central command tower. They are Built on land and then transported to their watery homes, the forts were designed by Guy Maunsell, a British civil engineer and named after his name .Each 300 tonne tower was preconstructed before being towed out to sea, sunk into position and then connected to the next tower.

 Army Fort (one of these fortsJ) was badly damaged in a storm and by being struck by a ship, and was dismantled in 1959-60. In the 1960s and 70s, the remaining abandoned forts were famously taken over as pirate radio stations.

These forts are now in varying states of decay, and any attempt to enter them is ill-advised, if not illegal. They can be seen by boat or, on a clear day, from Shoeburyness East Beach.