Zhangjiajie National Forest Park () is a national forest park located in Zhangjiajie, Hunan Province, China. It is one of several national parks within the Wulingyuan Scenic Area. History In 1982, the park was recognized as China's first national forest park with an area of . Zhangjiajie National Forest Park is part of a much larger Wulingyuan Scenic Area. In 1992, Wulingyuan was officially recognized as a UNESCO World Heritage Site. It was then approved by the Ministry of Land and Resources as Zhangjiajie Sandstone Peak Forest National Geopark () in 2001. In 2004, Zhangjiajie geopark was listed as a UNESCO global geopark. The most notable geographic features of the park are the pillar-like formations that are seen throughout the park. Although resembling karst terrain, this area is not underlain by limestones and is not the product of chemical dissolution, which is characteristic of limestone karst. They are the result of many years of physical, rather than chemical, erosion. Much of the weathering that forms these pillars is the result of expanding ice in the winter and the plants that grow on them. The weather is moist year-round, and as a result, the foliage is very dense. The weathered material is carried away primarily by streams. These formations are a distinct hallmark of the Chinese landscape, and can be found in many ancient Chinese paintings. One of the park's quartz-sandstone pillars, the Southern Sky Column, was officially renamed "Avatar Hallelujah Mountain" () in honor of the movie Avatar in January 2010. The film's director and production designers said that they drew inspiration for the floating rocks from mountains from around the world, including those in Hunan province. Structures The Bailong Elevator, literally "hundred dragons sky lift", was opened to the public in 2002. At , it is the world's tallest outdoor lift. It can transport visitors to the top from its foot in less than two minutes. The structure is composed of three separate glass elevators, each of which can carry up to 50 people at a time. In August 2016, Zhangjiajie Grand Canyon opened the Zhangjiajie Grand Canyon Glass Bridge, the longest () and highest () pedestrian glass bridge in the world. Thirteen days after opening, the bridge was closed due to the sheer number of visitors. On 30 September 2016, the bridge reopened after adjustments to its logistics and safety measures for handling a large number of tourists.