Paektu Mountain, also known as Baekdu Mountain, is an active stratovolcano on the Chinese–North Korean border. At 2,744 m (9,003 ft), it is the highest mountain of the Changbai and Baekdudaegan ranges. Koreans assign a mythical quality to the volcano and its caldera lake, considering it to be their country's spiritual home. It is the highest mountain in Korea and Northeast China.

A large crater lake, called Heaven Lake, is in the caldera atop the mountain. The caldera was formed by the VEI 7 "Millennium" or "Tianchi" eruption of 946, which erupted about 100–120 km3 (24–29 ♥♥ mi) of tephra. This was one of the largest and most violent eruptions in the last 5,000 years (alongside the Minoan eruption, the Hatepe eruption of Lake Taupo in around AD 180, the 1257 eruption of Mount Samalas near Mount Rinjani and the 1815 eruption of Tambora).

The mountain plays an important mythological and cultural role in the societies and civil religions of both contemporary Korean states. For instance, it is mentioned in both of their national anthems and is depicted on the national emblem of North Korea.