Deep in the ocean, off the coast of central California, lies a vast field of mysterious markings.
The field covers about 1,300 square kilometers and there are about 5,200 of these strange pits, which average about 175 meters and 5 m deep.
Nobody knows how these mysterious holes appeared, but they probably first appeared 400,000 years ago, according to research.
Coordinates: 33°39’17.76″N 118°7’5.82″W
A vast field of mysterious, perfectly circular holes dot the seabed off the California coast.