Simatai (Chinese: 司马台; pinyin: Sīmǎtái), a section of the Great Wall of China located in the north of Miyun District, 120 km northeast of the city center of Beijing, holds the access to Gubeikou, a strategic pass in the eastern part of the Great Wall.
Simatai Great Wall is separated by a valley into eastern and western parts.
The western part is gently sloped with 20 well-preserved watchtowers dotting along the wall.
The eastern part is much steeper, following more rugged terrain that includes cliff edges and kilometre-high peaks.
Hanging precariously onto the Yan Mountains, Simatai Great Wall is known for its steepness.