The former emergency relocations site for the government in the event of nuclear attack, the site has been abandoned since the 1980s since which time it has been kept as a decoy site until its declassification at the end of 2004. Burlington has had many code names since its conception in the early 50s, these include Stockwell, Subterfuge, Turnstile and more recently Site 3.
The Nettleden team dedicated to secret underground bunkers and tunnels in the UK. On their YouTube channel you'll find videos relating to underground and urban exploration.
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