The story begins about 540 million years ago, when the granite that forms the base of every mountain in Wadi Rum was cooling deep beneath the surface. Above it, for hundreds of millions of years, sand was deposited — at times by rivers, at times by shallow seas — pressed and hardened into the red and yellow sandstone you walk on today.
Then came the slow exposure. Continents moved. Climates shifted. The Arabian plate rose and tilted. Wind, rain and very occasional floods carved away the softer layers, leaving the cliffs and arches you see — granite at the base, sandstone above.
Jabal Um ad Dami, Jordan's highest peak at 1,854 metres, is the most southern of these formations. Jabal Rum, opposite the village, rises to 1,734 metres. Together they form a long backbone running north–south.
The most striking feature for visitors is the contact line on each mountain — a clear horizontal seam where granite ends and sandstone begins. It is the only place where you can stand at the boundary of two rock formations separated by tens of millions of years and touch both at the same time.
And look down: scattered in the sand are fossil shells, ripple marks frozen in stone, the patient handwriting of an ocean that came and went before mammals existed. Wadi Rum is a desert that has been many other things.