Some people dream about finding a dungeon underneath an old structure. However, researchers from the Texas A&M University took it a step further by finding an old military fortress underneath the former Alcatraz Federal Penitentiary.
Using ground penetrating radar, the research team was able to uncover what is left of a military fortress once known as Fortress Alcatraz, made popular by the Hollywood blockbuster, The Rock.
"We know from records and drawings that Alcatraz, at one time called Fortress Alcatraz, has been heavily fortified," said Mark Everett, a professor of geology and geophysics from then National Parks Service and the Chico State University in California.
Alcatraz is one of the most notorious prison facilities in the world. Due to the intense fascination of the general public with the island prison, historical accounts and mysterious rumors can often blend together making it difficult to construct an accurate timeline of events. However, historical records clearly indicate that the island was once an important military facility back in the mid 1800s.
"At one time, it had 105 cannons that were to be used to protect the Bay area. We know that the soldiers constructed what was called a 'caponier,' a large concrete and brick structure that extended outward so that if invaded, you could fire from different angles," Everett added.
The island originally once belonged to a Mexican governor named Pio Pico. Over the years, the island changed ownership a few times until it was later purchased by the United States government and set aside for military use.
"We also know that the U.S. Army built underground tunnels and embankments, and we believe we have found the remains of several of these using ground-penetrating radar," added Everett.
Everett and his colleagues found the remains of the old fort underneath the former prison facility's recreation yard and parade grounds. Since the fortress, and later on the prison, was built on an island, maintaining a facility on Alcatraz proved very costly. The costs of bringing in water to the guards and and prisoners proved too much for the government and the prison was shut down.
"One of the big problems that always plagued Alcatraz was water. It had none, and water had to be brought in to fill a water tower on the grounds," Everett said. "Water was always an issue with the facility."
The scientists working onsite found many structures that belonged to the old fortress. The presence of these structures could prove historically valuable, which is why the researchers are hoping to return to study the island further.
"We do believe there are considerable structures 12 feet or so under the surface that are the original fortifications and that these were covered over through the years for prison use," said Everett. "It's possible there could be some of the original weapons and arms down there, too."
