The extensive black basalt city of Umm Al-Jimal, anciently called "Black Gem of the Desert", lies like a dark encrustation on the flat desert of northern Jordan. So many of the buildings still stand to two, or even three, storeys that it seems as if its abandonment must have been within living memory - in fact it has been deserted for about 1200 years.

The ruins here reveals a wide range of structures typical of a modest provincial town that lacked a formal urban plan unlike the monumental splendor, architectural extravaganza, and imperial scale of towns such as Gerasa, Gadara and Philadelphia. Umm Al-Jimal, means "Mother of" either "Camels" or "Beauties" in Arabic, is one of the most truly impressive monuments of ancient civilizations.

The Nabataeans established a settlement here in the 1st century BC during their northerly expansion, perhaps as a staging post on the trade route between Damascus and the south. As there are no springs or wells, the entire water supply had to be collected during the rainy season in hundreds of cisterns.

Herod the Great drove the Nabataeans out of their northern domains around 30 BC, and the Romans soon extended their rule over the entire area. Umm Al-Jimal was greatly enlarged from the 2nd century AD onwards, and became an important military base - it was enclosed within walls; a new reservoir was built, as well as a sophisticated hydraulic system outside the city to supply its cisterns and reservoirs; and a vast, but now ruinous, fort was constructed - to be replaced under the Byzantines in the early 5th century by the much smaller, and well preserved, barracks, for by now the military role of the city had diminished.

Under the Byzantines Umm Al-Jimal continued to grow - many houses were built, 14 churches and a cathedral. It also flourished under the Umayyads - still with a Christian community - but earthquakes, especially that of 747 AD, caused considerable damage; and the Abbasid removal to Baghdad ensured that the city was never rebuilt. It remained abandoned until the early 20th century, when some Druzes from the nearby Jabal Addoruze took up brief residence here.