Yellow ducks roaming about the riverside in Changtang National Nature Reserve. The animal is under state-level protection. [Photo: Xinhuanet]

With an area of 29.8 million hectares, the Changtang National Nature Reserve is located in the north of Tibet. "Changtang" means "Highland in the North" in Tibetan, describing the vast grassland in the nature reserve. As the Changtang area has an average altitude of above 5,000 meters, it is dubbed as "the Roof of the Roof of the World", in which "Roof of the World" being the Qinghai-Tibet Plateau.

With the constantly improving ecosystem in recent years, the Changtang National Nature Reserve has become a paradise for many wild animals, including wild yak, Tibetan antelope and Tibetan dzigettai. Nowadays there are more than 1000 species of wild life inhabiting the area.