continent Eurasia The convention used in gaz.obo is that the Europe-Asia boundary follows the watershed of the Ural Mountains from near Kara, Russia on the Kara Sea to the source of the Ural River, then follows that river to the Caspian Sea. The border then follows the watershed of the Caucasus Mountains from the Caspian Sea to the Black Sea. continent Eurasia The convention used in gaz.obo is that the Europe-Asia boundary follows the watershed of the Ural Mountains from near Kara, Russia on the Kara Sea to the source of the Ural River, then follows that river to the Caspian Sea. The border then follows the watershed of the Caucasus Mountains from the Caspian Sea to the Black Sea.