The Jinshanling Great Wall is a complicated and well preserved fortification systems and possesses the largest number of watchtowers. These watchtowers were made by huge bricks, 5-8 miles high, and each one built in a different architectural style. The distance between each tower is about 50 to100 miles away. Some of them are half-timbered, some are stone, some with one eave, some with two-eave. The roofs of the towers are many and varied,...