The Kura is an east-flowing river south of the Greater Caucasus Mountains which drains the southern slopes of the Greater Caucasus east into the Caspian Sea. It also drains the north side of the Lesser Caucasus, while its main tributary, the Aras, drains the south side of those mountains. Starting in northeastern Turkey, the Kura flows through Turkey to Georgia, then to Azerbaijan, where it receives the Aras as a right tributary, and enters the Caspian Sea at Neftçala. The total length of the river is 1,515 kilometres (941 mi).

The Aras is a river in the Caucasus. It rises in eastern Turkey and flows along the borders between Turkey and Armenia, between Turkey and the Nakhchivan exclave of Azerbaijan, between Iran and both Azerbaijan and Armenia, and, finally, through Azerbaijan where it flows into the Kura river. It drains the south side of the Lesser Caucasus Mountains while the Kura drains the north side of the Lesser Caucasus. The river's total length is 1,072 km (666 mi) and its watershed covers an area of 102,000 km2 (39,000 sq mi). The Aras is one of the longest rivers in the Caucasus.