West Siberian Plain is the world largest lowland that is flanked from the west by Ural Mountain range, by Altay Mountains from the southeast and by Yenisei river from the east. The rich evidence for prehistoric and proto-historic cultures derives mostly from Ural and Altay mountain ranges and from the southern part of the plain. The region is unique due to the coexistence of Neanderthals and Denisovans ca 100-50 thousand years ago. The early Modern Humans dispersed into the region ca 50-45 thousand years ago.