isolate in the San Francisco Bay and surround by steep cliff fount , Alcatraz Federal Penitentiaryseemed like the most secure blank space to keep dangerous criminal in the mid-20th hundred . But it ’s recently come to ignite that every convict on Alcatraz Island lived above a series of likely escape routes that predated the prison house ’s construction , theSan Francisco Chroniclereports .
In a new study published in the journalNear Surface Geophysics , archaeologists cover their uncovering of structures and artefact beneath the Alcatraz prison curtilage , admit underground buildings , tunnels , and ammunition magazines . direct by historical maps , documents , and picture , they used laser scan technology and ground - penetrating radar to locate the subterraneous fortress close to the airfoil .
The situation date back to the mid-19th century , when Alcatraz Island was used for military purposes . The same natural features that would later make Alcatraz an likeable prison also made it an ideal coastal munition . Enough brick edifice were build there to put up 200 soldier and enough food was ship in to feed them for four months .
But the fortification was n’t used for its original purpose for very long . It was transformed into the West Coast ’s official military prison house during the Civil War , and in the 1930s , the government turned it into a federal prison house . alternatively of tearing down the forts and tunnels leftover from its military 24-hour interval , workers left them entire and built over them to save money . archaeologist plan to enquire the undercover structures further without disturbing the historical site .
Alcatraz Prison close in 1963 , so the clandestine tunnels no longer vex a security job . Today the island is part of theU.S. National Park Serviceand is a pop tourist attraction .
[ h / tSan Fransisco Chronicle ]
