There was two types, the army ones that look like they should be in 'War of Worlds', the walkways between the towers have largely rusted away and collapsed into the sea, but otherwise the individual towers are apparently in fairly good nick, despite being rusty on the outside.
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That mast isn't left over from the pirate stations in the 60s, it was erected back in 2007 and used by 'Radio Red Sands' for a few years, using a restricted service licence (RSL) for 10 days during the annual Whitstable Oyster Festival, and yes, I know a couple of the nutters that went out there to be it!
The navy forts, had living quarters actually in the legs, going down below sea levels, it's one of these that is Sealand, minus the very top bit, which was removed to make way for a helicopter landing pad.
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