Yueyaquan (Chinese: 月牙泉; pinyin: Yuèyá Quán) is a crescent-shaped lake in an oasis, 6 km south of the city of Dunhuang in Gansu Province,China. It was named Yueyaquan in the Qing Dynasty. Mildred Cable & Francesca French visited the lake during their travels in the region and recorded their impressions in their book The Gobi Desert, “All around us we saw tier on tier of lofty sand-hills, giving the lie to our quest, yet when, with a final desperate effort, we hoisted ourselves over the last ridge and looked down on what lay beyond, we saw the lake below, and its beauty was entrancing.”
According to measurements made in 1960, the average depth of the lake was 4 to 5 meters, with a maximum depth of 7.5 metres (25 ft) In the following 40 years, the depth of the lake continually declined. In the early 1990s, its area had shrunk to only 1.37 acres (5,500 m2) with an average depth of 0.9 meter (maximum 1.3 meter). In 2006, the local government with help of the central government started to fill the lake and restore its depth; its depth and size have been growing yearly since then. The lake and the surrounding deserts are very popular with tourists, who are offered camel and 4×4 rides.
Research has discovered that in this special crescent landform the wind created this depression, as the cross-ventilated theory states, the falling sands from the surrounding mountains would be sent back to the other side of nearby Echoing-Sand Mountains. Thus, the sands do not smother the spring. And this particular earth movement keeps the sand dunes and spring eternally in a harmonious and almost paradoxical existence.