For more than a century, people in the Bay Area — and especially the East Bay — have puzzled over the existence of stone walls scattered on ridges from near San Jose north through the Berkeley Hills.

Sometimes the walls are built in long straight lines. Sometimes they form angles. Occasionally you’ll find rectangular or circular constructions.

Who built these things? How long ago? And why?

Maybe voyagers from a lost continent built them. Or visitors from outer space. Or a vanished tribe of “superior” Native Americans.

People have suggested these walls could have been meant for defense. Or as navigational aids for extraterrestrials. Ancient walls leading to a mysterious stone circle
The East Bay “Mystery Walls”, extending for more than 50 miles in length, are easily spotted up and down the hills . It is strange enough to witness such long wall, but the question lies in the possibility of other walls as well. Maybe the Berkeley wasn’t the only one here.

It turns out that other enigmatic walls in North California exist, not just lying around the San Francisco Bay Area, extending even to the Oregon border. The walls stretch across the Oakland hills, heading inland towards Mount Diablo, in which there are enigmatic rock circles roughly 30 ft. in diameter. The walls create a spiral 200 ft. wide that surrounds a big boulder in one place.

Who were the mysterious builders of the Great Wall of California?
The rock walls might have been products from Mongolian or Chinese settlers, who often wall in their cities, according to archaeologists conducting excavations on site. The enigmatic walls resemble the features of the Great Wall Of China.

Perhaps the fleet of Zheng He, with the purpose of global circumnavigation, did reach California. Traces including anchors discovered in Baja California, strange scripts from a Buddhist monk in Meso America, and a sunken 17th century Junk discovered near Chico may indicate that Chinese explorer arrived in this region.

Other theories mention that the walls were actually constructed by the very first missionaries. Yet, other scholars still questions whether Sir Frances Drake did not leave colonists behind at the site where he completed the circumnavigation of the globe.

There are also opinions that the Ohlone, a a Native American Indian tribe raised the wall. Still, there is too little evidence to confirm the hypothesis like the other theories.

The Great Wall of California builders’ identity remains unsolved
The wall is up to five feet tall in some places, and it was constructed from boulders of varying sizes. Some are basketball-sized rocks, while others are large sandstone boulders weighing a ton or more. Many of the stones are pretty heavy, and the entire site appears to be very old. Many of the formations have sunk far into the earth and are often entirely overgrown with different plants.

The purpose of the walls is unknown. At first sight, one might think it was defense construction of some kind, but there are certain problems with this theory. The wall is not continuous, and it is composed of multiple sections. In addition, the wall is not high enough to have been used as a defense mechanism.

It is therefore doubtful it was used as a fence. So, why was it built?

Archaeologists and scientists have not investigated this curious and interesting ancient site in more detail. Unfortunately, the walls haven’t been subjected to a serious scientific examination. For now, the Berkeley Walls remain an ancient unsolved North American mystery.