Ur (Arabic أور) is the ancient city located at تل المقير Tell alMuqayyar, an Arabic name meaning Mound of Pitch that derives from the baked bricks set in bitumen that litter the site.
Ur is associated with the Ur of the Chaldees mentioned in the Bible as Abraham's birthplace (Gen 12:4-5), though Urfa in Anatolia also is associated thusly. It was inhabited circa 5500 to 400 BC, finally being abandoned due to difficulties with its water supply. During its habitation, Ur was a politically, economically and religously powerful city -- especialy during the 3rd millenium BC, with easy access to the Persian Gulf and long-distance sea trade.
Ur contained a temple to the moon-god Sin, whose cult was of central importance at Ur (Jastrow 1915, p 28). Inscribed bricks traced the temple's construction to the Ur dynasty, which flourished in the 3rd millennium BC (Jastrow 1915, p 29). There were early Babylonian coffins, much smaller than the Neo-Babylonian and Persian Period slipper-shaped coffins. These sarcophagi ranged from narrow deep tubs (where the body must have been semi-upright) to large covered dishes.
In 1922 -- the same year that Howard Carter thrilled the world with his discovery of Tutankhamen's tomb in Egypt -- a little-known British archaeologist named Charles Leonard Woolley began excavations at Ur. His most remarkable discovery was a massive cemetery with thousands of burials, including a small number of rich tombs belonging to Ur royalty circa 2500 BC. This was the famous Royal Cemetery of Ur. Woolley excavated on an enormous scale, focusing initially on public buildings and the ziggurat. Next, he turned to the Royal Cemetery (with 2000 simple burials from 2600 - 2100 BC; and 16 royal tombs circa 2500 BC). The remains of court attendants interred by human sacrifice with the kings and queens shocked global audiences. Later, Woolley focused on Ur's prehistory and found a thick layer of silt above the earliest occupation layers: he cited Gilgamesh and the Bible (Gen 6-9) to speculate he had found the great flood strata. Woolley routinely referenced Ur's biblical significance with the floor and Abraham's birthplace to attract public attention.