Even with favourable tides it still takes an hour from land to reach these isolated monsters. They were constructed during the second world war, based on a clever design by a chap called Guy Maunsell, and their sole intention was to save London from Nazi bombs and rockets. Although not built until after the main blitz of London they did their job. Collectively they shot down 22 enemy aircraft and 30 V1 flying bombs, no doubt saving untold casualties in the process. Five structures circle a central command and accommodation block, along with a seventh which used to house the search lights. Bridges once spanned the gaps between them so as you could walk from one to another, but along with the access ladders these have long since been removed. Since WWII they have been home to various attempts at pirate radio stations, but some of the structures are believed not to have had any human visitors for at least 50 years as they now stand abandoned and in desperate need of maintenance less they end up as some of the similar forts such as the Nore forts, off Sheerness which are now demolished.