Tianmen Mountain, Mountain summit in Zhangjiajie, China.

Tianmen Mountain is a 1,518.6 m summit in Tianmen Mountain National Park, Zhangjiajie, Hunan Province. Its natural arch, Tianmen Cave, is a 131.5 m opening in the rock reached by a 999-step stairway, the "Stairway to Heaven", flanked by white stone balustrades and small tiled pavilions. An 11 km road with 99 bends, Tongtian Avenue, also climbs to the arch.

The natural arch of Tianmen Cave, 131.5 m high, pierces the mountain above the 999-step Stairway to Heaven. On the summit, the original Tianmenshan Temple was built during the Tang dynasty and destroyed in the first part of the 20th century; construction of a new temple in Tang style began in 1949. In 2005 the French company Poma built the cableway from Zhangjiajie railway station to the summit.

The name Tianmen Shan means "Heaven's Gate Mountain", after the 131.5 m natural arch in the rock, called Heaven's Door. The 999 steps up to the arch are known as the Stairway to Heaven. On the summit stands Tianmenshan Temple, rebuilt from 1949 in Tang dynasty style, which houses a vegetarian restaurant.

The cableway built by Poma in 2005 runs from Zhangjiajie railway station to the summit, 7,455 m long with an ascent of 1,279 m. Tongtian Avenue, an 11 km road with 99 bends, also climbs to the arch. The arch itself is reached by the 999-step Stairway to Heaven, and paths along the cliff face at the top include glass-floored sections.

A winding road with 99 bends climbs from the valley floor to the cave, following the tight folds of the mountain. This road is used for racing events, with drivers navigating the steep switchbacks upward.