A Tianchi Lake lies in the deep Greater Hinggan Mountains in Chaihe, Zalantun of Inner Mongolia autonomous region. Photo taken on May 29, 2010. According to the Institute of Geography and Geophysics, Chinese Academy of Sciences, Chaihe, one of the volcanic landforms in East China, was found housing the largest-ever volcanic lake groups in China in recent years, with 15 giant craters, seven volcanic lakes located on mountains over 1,000 meters above sea level and a 13-kilometer volcanic rift zone. Lying at the top of the volcanic cone of the main peak, the lakes form the shape of a lotus leaf and a natural result of volcanic eruption. [Photo/Xinhua]