‘The Maunsell Sea Forts were small fortified towers built in the Thames and Mersey estuaries during the Second World War to help defend the United Kingdom. They were named after their designer, Guy Maunsell. The forts were decommissioned in the late 1950s.’
Interesting account of a guy who lived out on one of these for a month in 2024
http://www.seafort.org/menu.html
Wow, I can see where the idea for the Star Wars AT-TE walkers came from!
Some of these were used by pirate radio broadcasters in the 60′s as an alternative to the radio ships, such as Radio Caroline, that were anchored outside territorial waters. The most powerful was Radio 390, a “soft music” station that put out a colossal signal on AM from its huge mast. I think the forts may have had interconnecting walk-ways that have since rotted and fallen away.
I love these
I am so proud these have been featured as I don’t live far from these 
Ha.Reminds me of that episode of Secret Agent Man where he goes up against these people who are operating a pirate radio station on one of those things.the BBC must have really suckedback then for them to have gone to that extreme.
Look at these, and then look at the invading monsters in the pulp fiction versions of HG Wells’ War of the Worlds
The one in the 3rd picture is the principality of Sealand, my homeland.
I have a Lordship from Sealand
I don’t suppose anyone realized…