Introduction to the Great Wall on the Waterfront: When the Great Wall in my country was built, it was built close to mountains and rivers and with local materials. However, no part of the Great Wall can reflect the closeness to mountains and rivers in an area of ​​about 7.8 square kilometers. , a three-dimensional military defense system composed of a 15-18-meter-high Grand Canyon, a unique Tibetan Soldier Cave, and the garrison's castle.