Ubar is spoken of in ancient records and in folk tales as a trading center of the Rub al Khali Desert in the southern part of the Arabian peninsula. It is estimated that it lasted from about 3000 B.C to the first century A.D. It became, according to legends, fabulously wealthy from trade of the coastal regions to the population centers of the middle-east and even into Europe. The city became lost to modern history, and was thought to be only a figment of mythical tales.

In the early 1980s a group of researchers became interested in the history of Ubar. They used remote sensing data from NASA, and identified old caravan routes and the point at which they converged. Excavations uncovered a fortress which protected the caravan routes and the all-important water source, which was a large limestone cavern underneath the fortress. Evidence of wide-spread trade was also found. An earthquake apparently broke open the water cavern and thus the water source was lost, after which the city fell into oblivion.

In reality, Ubar was not the name of the city, but the name of the region. Ptolomy created a map in the second century map which identified the area as "Iobaritae," or in other words, the Ubarites. The Koran referred to them as the people of Ad. Later legends referred to the fabulous wealth of the city and used the region name Ubar to designate it.