Oasis scenic spot in Gobi Desert, NW China

Tourists ride camels as they visit the Mingshashan, literally "singing-sand mountain", an oasis scenic spot in the Gobi Desert in Dunhuang, Northwest China's Gansu province, June 17, 2014. (Xinhua/Nie Jianjiang)

Tourists visit the Mingshashan, literally "singing-sand mountain", and the Crescent Lake, an oasis scenic spot in the Gobi Desert in Dunhuang, Northwest China's Gansu province, June 17, 2014. (Xinhua/Nie Jianjiang)

Tourists visit the scenic spot of the Yangguan Pass, some 70 kilometers northwest of Dunhuang city along the ancient Silk Road in Northwest China's Gansu province, June 17, 2014. (Xinhua/Nie Jianjiang)

Tourists visit the relics of Yumen Pass, some 90 kilometers northwest of Dunhuang city along the ancient Silk Road in Northwest China's Gansu province, June 17, 2014. (Xinhua/Nie Jianjiang)