The wall of the United States was once the most popular tourist attraction in the world, but it has been damaged by a series of storms, earthquakes, and landslides that have eroded the fragile structures into the desert.
The destruction has created a wall that is now almost as steep as the Earth’s crust.
Now, a team of geologists and researchers from the University of California, Berkeley has mapped a network of ancient rock outcroppings that they believe may hold the key to understanding the wall’s history.
This video shows a wall of stone and sand that sits beneath a cliff that once stood between the wall and the California coast.
The site was once an outcrop of limestone that rose up from the floor of the San Francisco Bay.
The ancient wall is roughly two feet (610 centimeters) thick and can stand upright up to 2,300 years, the researchers say.
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