Tumen River

The Tumen River is a 521 km-long river that serves as part of the boundary between China, North Korea, and Russia, rising in Mount Baekdu and flowing into the Sea of Japan.

The river flows in northeast Asia, on the border between China and North Korea in its upper reaches, and between North Korea and Russia in its last 17 kilometers (11 mi) before entering the Sea of Japan. The river forms much of the southern border of Jilin Province in Northeast China and the northern borders of North Korea's North Hamgyong and Yanggang provinces. Baekdu Mountain on the Chinese-North Korean border is the source of the river, as well as of the Yalu River (which forms the western portion of the border of North Korea and China).

The name of the river comes from the Mongolian word tümen, meaning "ten thousand" or a myriad. This river is badly polluted by the nearby factories of North Korea and China; however, it still remains a major tourist attraction in the area. In Tumen, Jilin, China, a riverfront promenade has restaurants where patrons can gaze across the river into North Korea. Russian name of the river is Tumannaya, literally meaning foggy.

In 1995, the People's Republic of China, Mongolia, Russia, and South Korea, signed three agreements to create the Tumen River Economic Development Area.

Important cities on the river are Hoeryong, Namyang and Onsong in North Korea, Tumen and Nanping in China.