The Badain Jaran Desert is a desert in China
which spans the provinces of Gansu
and Inner Mongolia
. It covers an area of 49,000 sq. kilometers (19,000 sq. miles).This desert is home to the tallest stationary dunes on Earth. Some of the dunes reach a height of 500 meters (1,600 ft.). The dunes are kept in place in the arid, windy region by an underground water source. Analyses of the ground water indicates that it is snowmelt that flows through fractured rock from mountains hundreds of kilometers away.
The desert also features over 100 spring-fed lakes that lie between the dunes, some of which are fresh while others are extremely saline. These lakes give the desert its name which is Mongolian for "mysterious lakes". It is also crossed by one river, the Ruo Shui ("weak water"), which has formed a great alluvial plain in the desert.