Dilmun features both in Mesopotamian myth, as a blessed land where death is unknown, and in the trade records of the Mesopotamian city of Ur as a real place, the source of Ur's copper supplies. The quest for the real Dilmun began in a relatively light-hearted way in 1953, when Geoffrey Bibby seized the opportunity to revisit Bahrain, in order to explore the thousands of undated burial mounds that decorate the Bahraini landscape. A brief season's digging was enough to establish the existence of a major civilization dating from around 2300 BC, contemporary with Ur and Babylon and showing evidence of trade with the Indus Valley civilization. Thus began a major undertaking, eventually encompassing more than 20 annual expeditions. These revealed the existence of cities and temples not only on Bahrain, but along 250 miles of coast and islands as far north as Kuwait and extending 60 miles into the interior of Saudi Arabia, as well as a second and earlier civilization some 300 miles east, in Oman, which Bibby identified with the legendary copper-rich land of Makan. And the final extraordinary revelation was the discovery in Saudi Arabia of pottery contemporary with the very earliest Stone Age settlements in Mesopotamia, c.5000 BC, extending the early history of the Gulf region back by over 1000 years and raising the possibility that Mesopotamia was first settled from Arabia.