The importance of metals in human history was recognised long ago by early archaeologists and anthropologists interested in social evolution. Of the base metals used in the Old World (Europe, Africa, Asia) in the past, copper was surely the most important until c. 1000 BC when iron came to prominence. In the UAE copper sources have been located in the Hajar mountains, specifically in southern Ras al-Khaimah and Fujairah, and evidence of copper refining ('smelting') is abundant at several sites such as the Wadi Safafir and Awhala. The use of refined copper to cast objects in moulds, such as tools, weapons and pieces of jewellery, is shown at sites such as Tell Abraq and Muweilah, where hundreds of tiny droplets of casting spillage have been recovered along with pieces of finished workmanship. Around 2100 BC the land of Magan was an important supplier of copper to the cities of southern Mesopotamia, and sites like Umm al-Nar and Tell Abraq may have been outlets on the coast for trade with city-states like Ur and Lagash in what is today southern Iraq.