Human habitation of Qatar dates back to 50,000 years ago. Settlements and tools dating back to the Stone Age have been unearthed in the peninsula. Mesopotamian artifacts originating from the Ubaid period (c. 6500–3800 BC) have been discovered in abandoned coastal settlements. Al Da'asa, a settlement located on the western coast of Qatar, is the most important Ubaid site in the country and is believed to have accommodated a small seasonal encampment.