Southwest Kazakhstan is a C-shape, surrounding the northeastern end of the Caspain Sea, the world's largest salt lake. The lower end of the 'C' is the Mangyshiak Peninsula. Around the inner curve of the 'C' are the Pre-Caspian Lowlands, former lake beds, now dry but below sea level. East of the lowlands, in the fat bottom of the 'C', is the Ust-Urt Plateau, whose limited rise is attested by its being grouped into the Turanian (or Turkestan) Lowlands. Two rivers of note cross the 'C' to enter the Caspian: the Ural from the north, marking the Europe-Asian boundary, and the Emba from the northeast. The southwest bound of Atyrau Province is at the edge of the Volga River delta.