US Civil War-era tunnels and buildings found under Alcatraz prison
A new study has found US Civil War-era tunnels and buildings buried beneath the famed Alcatraz island prison in San Francisco, California.
Historians had long-suspected that the notorious federal penitentiary had been constructed atop US military fortifications built in the 1800s.
A study published last week in Near Surface Geophysics describes the complex found beneath the prison yard.
The now-closed jail imprisoned some of the worst criminals in US history.
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Read more at: https://www.bbc.com/news/world-us-canada-47475564
Definitely, something to read and research on more.
