Following the post-glacial flooding of the Persian Gulf basin, debris from the Tigris–Euphrates river formed a substantial delta, creating most of the land in present-day Kuwait and establishing the present coastlines. One of the earliest evidence of human habitation in Kuwait dates back to 8000 BC where Mesolithic tools were found in Burgan. Historically, most of present-day Kuwait was part of ancient Mesopotamia.During the Ubaid period (6500 BC), Kuwait was the central site of interaction between the peoples of Mesopotamia and Neolithic Eastern Arabia, including Bahra 1 and site H3 in Subiya.
