Lost city of...

A city formed as early as the 1st century BC, X was a thriving city state in the present day Jordan near the Dead Sea with a lot of the spice trade being carried out majorly from X. the people of X were called Edomites (Edom meaning red), due to the colour of the rocks found in the region. The city flourished under the subsequent Roman rule but after a series of earthquakes from 3rd to 7th century AD destroyed the city, it was lost in time. X was discovered in 1812 by a Swiss explorer and has since then become famous for its unique hydraulics systems and the unique architecture. It is most well-known for its treasury which is built right inside the desert rocks. Id X.