The Great Wall of Berkeley (California) extending for more than 50 miles

https://imgur.com/fmoHRKN

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.


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