They look like Imperial AT-AT Walkers out of The Empire Strikes Back, but these nautical oddities have nothing to do with George Lucas' imagination. They're naval sea forts, located in England's Thames Estuary, and were designed by Guy Maunsell in 1942 to provide anti-aircraft fire for the London area.
Today they're in less than perfect condition, so if you were hoping they housed boutique hotels, you're out of luck. In fact they're pretty dangerous to enter at all. They've been buffeted by storms and crashed into by ships, and although they were used as pirate radio stations in the 1960s, they're a little too rickety to be used any more.
Of the forts that were built, only Red Sands and Shivering Sands remain, standing as eerie relics of a bygone age. If you want to know more about them, Barry Stewart has documented them, as well as many other curious historical sites, on his intriguing website, Underground Kent.
He lists countless military fortifications, underground tunnels and caves, ammo sites and Cold War submarines. It's well worth a trawl. Though many of the locations are on private land and not visitable, some are – and could make a great alternative tour of southern England. RM
Images: copyright Undergroundkent.co.uk