In the inscrutable Grand Canyon, it has been preserved for more than 500 years in the Ming Dynasty Tibetan cave, which is more magical by relying on the majestic Great Wall, the steep cliffs, and the mysterious ancient castle. It is one of the three-dimensional military defense systems used by soldiers guarding the border gates in the Ming Dynasty to defend against foreign enemies. The wisdom of the ancients, reflected here in the incisive, breathtaking.