Prehistoric Asia refers to events in Asia during the period of human existence prior to the invention of writing systems or the documentation of recorded history. This includes portions of the Eurasian land mass currently or traditionally considered as the continent of Asia. The continent is commonly described as the region east of the Ural Mountains, the Caucasus Mountains, the Caspian Sea and Black Sea, bounded by the Pacific, Indian, and Arctic Oceans. This article gives an overview of the many regions of Asia during prehistoric times.