Jinshanling, is a section of the Great Wall of China located in the mountainous area in Luanping County, Hebei Province, 125 km northeast of Beijing. This section of the wall is connected with the Simatai section to the east. Some distance to the west lies the Mutianyu section. Jinshanling Great Wall has been restored for easier climb. Visitors can hike all the way from Jinshanling to Simatai west. The Great Wall at Jinshanling has complete defensive system including barrier walls, battlement walls, watchtowers, gun emplacements, shooting holes, horse blocking walls, and branch cities. Located about 80 miles (130 kilometers) northeast of Beijing downtown, visitors can take a bus nearby Wangjing West Subway Station to get there. It is situated on the Big and Small Jinshanling Mountains, hence its name. It was constructed under the direction of general Xu Da in 1368 during the Ming Dynasty (1368-1644), and renovated under the supervision of the great general Qi Jiguang and the local governor Tan Lun in 1567. It zigzags from Longyu Pass in the west, and ends at the Wangjing Tower in the east, with a total length of 6.5 miles (10.5 kilometers), a height of 16 feet (5 meters) to 26 feet (8 meters), and an altitude of 2,297 feet (700 meters) above sea level. It has 67 watchtowers, 3 beacon towers, and 5 passes. They are densely distributed, at intervals of 55 yards (50 meters) to 110 yards (100 meters). The watchtowers differ in construction materials, the number of tiers, and the patterns of roofs. Some of them are made of bricks and wood, while others are made of bricks and stone. Some has one storey, while others have two or three. The roofs of the watchtowers also vary, including domes, flat roofs, square ones, and octagonal ones.