It's one of the great mysteries of the ancient world. Baigong in the Qinghai Province of China is crowned by a strange pyramid-like structure, full of caves that contain perfectly symmetrical, time-eaten metal pipes. They're inserted deep.
People have been finding strange holes in Russian forests. This has been occurring since the end of the These deep holes that appear suddenly in the dense forests, in those places that no truck or car can get to, let alone drill anything.