Along the border of China and the Democratic People's Republic of Korea lie the Changbai Mountains. On the top of the main peak of Changbai Mountain is Tianchi Lake, the highest volcanic lake in the world and the deepest of its kind in China. The icy Tianchi lake begins to melt around June. During peak seasons, namely June through September, hundreds of flowers blossom on the southern and western slopes - making it an ideal place for escaping from the summer heat.