Archeologists Find Hidden Tunnels Below Alcatraz Prison

March 7, 2019 Updated: March 7, 2019

SAN FRANCISCO—Archaeologists confirmed a long-time suspicion of historians and say that the famed Alcatraz prison was built over a Civil War-era military fortification.

Researchers found a series of buildings and tunnels under the prison yard of Alcatraz Federal Penitentiary, which once held Al Capone, SFGate reported on March 5.

Alcatraz Federal Penitentiary
The entrance of Alcatraz Federal Penitentiary. (Elwood J Blues/Wikimedia Commons)

A study published last week in “Near Surface Geophysics” said archaeologists used ground-penetrating radar, terrestrial laser scans, and historical maps and photographs. They found fully buried structures, ammunition magazines, and tunnels.

“This really changes the picture of things,” study author Timothy de Smet, an archaeologist at Binghampton University, told PBS. “They weren’t erased from the island—they are right beneath your feet.”

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People walk through the citadel, also known as the dungeon, during a tour of newly restored areas on Alcatraz Island in San Francisco, on July 1, 2015. (Eric Risberg/AP Photo, File)

Archaeologists are now planning more study to discover what else lies just below the surface.

Historians believe workers built over existing structures when the prison was built in the 20th century.

Alcatraz first came to the attention of the United States government after it took control of California from Mexico in the 1840s. Its location in San Francisco Bay made it attractive for military fortification purposes.

During the Civil War, Fort Alcatraz was the official military prison for the West Coast.

In the 1930s, the first federal prisoners—deemed by the media to be the worst of the worst—began arriving. The last inmate left in 1963.

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Jim Breeden of the Golden Gate National Parks Conservancy walks through the dungeons below the main cell house during a night tour on Alcatraz Island in San Francisco on July 7, 2011 (Eric Risberg/AP Photo, File)

Bones Found in Revolutionary War Graves Reveal More Details

LAKE GEORGE, N.Y.—The New York State Museum says it has learned more about the skeletal remains of 13 people discovered at a construction site where a Revolutionary War-era cemetery was located.

Archeologists say hand excavation of the Lake George site confirmed 11 graves contained the partial remains of 13 people, including seven adults over 20 years of age and six individuals younger than 20. Museum official says fragmentary remains of at least five other people also have been recovered.

The remains were first unearthed on Feb. 7.

The museum says buttons found in one of the graves was from the First Pennsylvania Battalion, which was in the Lake George area during the Revolutionary War.

Museum officials say they are working to confirm the age and origin of the graves, and analysis is expected to take several months.

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