Researchers have discovered tunnels and buildings from the time of the American Civil War, buried under the famous prison of Alcatraz Island in San Francisco, California.
Historians have long suspected that a federal prison was erected on the site of military fortifications built in the 1800s. The publication of the journal Near Surface Geophysics, describes the complex, found under the prison yard.
The study of the territory of the national park was conducted using ground penetrating radar and ground scanning. Under the recreation yard of the prison, researchers found traces of completely buried buildings, ammunition depots and tunnels. βThese ruins are well preserved and are located close to the surface,β said Timothy de Smet, an archaeologist at Binghamton University. He added that these artifacts are right under their feet. Armed with new evidence, researchers plan to continue to study the remnants of old structures.
Archaeologists began exploring most of the 19th century fortress buried under existing prison buildings in 2014. During work on the territory of Alcatraz, scientists were surprised by the concrete reinforcement of some earthen tunnels, despite the fact that concrete was not used in construction at that time.
βIt is interesting that at that time they did not even produce cement in the United States,β said Tanya Vattenburg Comas from California State University Chico. βIt was probably cement brought in barrels from Europe. Finding it on a mid-19th century battery was a big surprise.β
During the American Civil War, Alcatraz Island served as a military base that backed supporters of the West Coast Confederation. The defenses were built in the mid-1850s and included barracks and gun batteries. While most of the country was drawn into a bloody battle, Alcatrazβs fortress remained calm.
In addition, Fort Alcatraz was used as the official military prison of the west coast. The first prisoners from the federal penitentiary system began arriving in the 1930s, and the last were evicted in 1963. On an island with a high level of security, famous prisoners were serving sentences: Al Capone, George βmachine gunnerβ Kelly, Whitey Bulger.
By author Milena Moskvich