159 “Ground-Penetrating Radar Reveals Military Structures Buried Beneath Alcatraz Penitentiary Using non-invasive techniques, archaeologists have confirmed the presence of a coastal fortification beneath what was once the prison’s recreation yard. (twitter.com) posted 1 year ago by Joys1Daughter 1 year ago by Joys1Daughter +159 / -0 33 comments share 33 comments share save hide report block hide replies
Wonder how many prisoners went missing and using trying to escape as a cover
Good question...