The Nakpak Lake, located in Shangri-La County in the northwest of Yunnan Province, is a seasonal lake surrounded on three sides by mountains of 3,800 to 4,449 meters.

Every year it undergoes a radical transformation from resembling a small sea to becoming an alpine swamp meadowland. There are only a few alpine swamp meadowlands in Yunnan Province, and the Nakpak Lake is only one of them.

"The lake behind the forest", as its name means in Tibetan, grows in the late summer and early autumn and supplies water to the Green Dragon Pond, Nagchu River and Wangchuk River. During these seasons the water can cover a surface of thousands of hectares, resembling a small sea.

Throughout the rainy season, most of the grasslands are covered in water. Outside of this time, however, the water dries up and the lake dissolves into an alpine swamp meadowland.

It is one of Yunnan's most distinctive sights and is also the county's largest grassland area. Here the climate is humid, enabling various kinds of wildflowers to bloom.

The Nakpak Lake Nature Reserve is a nationally protected habitat for the black-necked cranes, which come to rest here every year for about six months from September to March.

It is believed that there are only about 1,000 black-necked cranes in the world, all of which live on the Qinghai-Tibet Plateau in summer, and spend winter on the Yunnan-Guizhou Plateau at Nakpak Lake, as they have been doing for thousands of years.

Among the people who live around the lake, there is a saying "Coming on Sept. 9 and going on Mar. 3", which shows the migratory habit of black-necked cranes  harmoniously sharing the Nakpak Lake environment with people.

Photo shows Nakpak Lake in Shangri-La County, northwest Yunnan Province. [Photo/ Xinhua]

Photo shows Nakpak Lake in Shangri-La County, northwest Yunnan Province. [Photo/ Xinhua]

Photo shows Nakpak Lake in Shangri-La County, northwest Yunnan Province. [Photo/ Xinhua]

Photo shows Nakpak Lake in Shangri-La County, northwest Yunnan Province. [Photo/ Xinhua]

Photo shows Nakpak Lake in Shangri-La County, northwest Yunnan Province. [Photo/ Xinhua]