The Zhangjiajie National Forest Park is a unique national forest park located in Zhangjiajie City in northern Hunan Province in the People's Republic of China. It is one of several national parks within the Wulingyuan Scenic Area. The most notable geographic features of the park are the pillar-like formations that are seen throughout the park. They are the result of many years of erosion. The weather is moist year round, and as a result, the foliage is very dense. Much of the erosion which forms these pillars are the result of expanding ice in the winter and the plants which grow on them. These formations are a distinct hallmark of Chinese landscape, and can be found in many ancient paintings. One of the park's quartz-sandstone pillars, the 1,080-metre (3,540 ft) Southern Sky Column had been officially renamed "Avatar Hallelujah Mountain" in honor of the eponymous film in January 2010.