Lake Chon is a crater lake on the top of Mt Paektu, the sacred mountain of the Korean revolution, in Samjiyon City, Ryanggang Province.
It was formed with water gathered in the crater after the eruption of a volcano.
The volcano has undergone four rounds of eruption and dormancy from the late Tertiary up to now.
The peaks surrounding the lake consists of rocks of basalt, trachyte, rhyolite, etc.
Mt Paektu rises 2 750 m above sea level and the water surface of the lake is 2190.15 m.
Covering an area of 9.17 square kilometres, the lake is 14.4 kilometres in circumference and 384 metres at its deepest.
The gross volume of water is 1 955 million cubic metres. The source of lake water is rainwater and melting snow and partially magmatic water.
The water flows down into the Amnok and Tuman rivers of Korea and the Songhua River of China.
The water is green in colour and freezes from early December to mid-June next year. The thickness of ice is 1.5 m on average. Some places with spas do not freeze even in winter.
The environs of the lake are covered with snow for over nine months from late in September to the end of June next year.
The annual average temperature of the lake is -4.9℃ and that of its water, 2.2℃.
By the lake there are Paektu, Paegam and other spas, and 168 species of plants, 16 species of birds, 6 species of mammals and 110 species of insects. And chars and goldfishes released artificially live in water.
As the deepest natural lake in Korea with superb and peculiar scenery, it is registered as a natural monument and under conservation.