Paektu

The land border is 636 miles long (1,025 km), most of it with China but the last 11 miles of it at the eastern end, with Russia. The border follows two rivers, the westward-flowing Yalu and the east-flowing Tumen, both of which arise from springs on the slopes of Mount Paektu, the sacred peak that is part of the "Ever-white Mountains" on the northeastern border.