Our Pick
Posted on @rawstates
Alcatraz cellhouse
1934
San Francisco Bay, California
Brian.S.W · CC BY-SA 4.0 · Wikimedia Commons
Federal penitentiary from 1934 to 1963, holding Capone and 'Machine Gun' Kelly. Of 36 who attempted escape, three vanished in 1962 and were never found.
That was 1 of the hidden places.
Location: documented spot
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