The limestone basins is in northern Sichuan Province, west-central China, in the southern part of the Min Shan Range about 230 km north of Chengdu.

The limestone basins is in northern Sichuan Province, west-central China, in the southern part of the Min Shan Range about 230 km north of Chengdu. The Scenic Area is divided between two sites: Huanglong valley, 45 km northeast of Songpan town, which also includes the whole Fujiang river catchment above Shijiabao village; and the Muni valley, 15 km south-west of Songpan, which includes the catchments of the Zhaga travertine waterfall and the Erdaohai mineral lakes.

This is an outstanding karst landscape within the southern part of the Min Shan range which runs from the eastern Qinghai-Tibetan plateau down to the Sichuan basin. The Huanglong section of the reserve covers the catchment of 22 tributaries of the upper Fujiang River which has its source in Snow Mountain Ridge. The Huanglong valley itself is one of these tributaries. The slopes above the valleys are forested and steep, a spectacular example being the 15km long 700m deep Danyun Gorge of the Fujiang near Huanglong valley. Above the tree line the site is surrounded by mountains, their strata tilted into jagged peaks, three bearing glaciers, seven over 5000m high and all snow-covered for much of the year. The pyramidal summit of Xuebaoding (Snow-Treasure Peak) is permanently snow-covered and carries the easternmost glacier in China.

Scenically the major attraction is the 3.6 km-long travertine formations of Huanglong Gou: Valley of the Yellow Dragon. These consist of clusters of over 3,300 brightly colored pools cascading over travertine terraces, travertine shoals, rapids and waterfalls. Caves also extend beneath the valley. The intense colours of the pools which vary between blue, green, yellow and milky are caused by the high calcium bicarbonate content of the water. This is precipitated biologically through the presence of great numbers of microscopic mosses which under certain conditions of temperature and turbulence attract the precipitation of calcite in underwater sills which grow upwards to form natural weirs (HNNCAA, 2001). But the biggest formation in the valley is Jinsha Pudi (Golden Sand Beach), an extensive sloping shoal of yellowish tufa (porous calcium carbonate) 1.3 km long and 125m at its widest which is the site of active limestone deposition under a thin layer of flowing water. This long uninterrupted limestone slope is thought to be the largest such formation in the world, and its color gave rise to the name Yellow Dragon.

In recent years several hotels were constructed in Songpan and Chuanzhousi, 42 km west of Huanglong. In the Huanglong reserve two hotels within the administrative area in the Fujiang valley offer tourist accommodation. Most visitors come in coach tours which last up to a week and also include a visit to Jiuzhaigou Scenic Area