The Overhanging Great Wall 懸壁長城 is the northern extension Jiayuguan Pass and part of the defense system of Jiayuguan. It was initially constructed in 1539 during the Ming Dynasty using locally sourced gravel and rammed earth on a 45-degree ridge of the Black Mountain. Its name derives from resembling hanging upside down in the sky. Only 750 meters of it remains. After restoration in 1987, it consists of a ramp walkway, parapet walls, and three beacon towers. It sits roughly 8 kilometers (5 miles) to the northwest of the main Jiayuguan Fortress.