The secrets of a lost city

VAST stacks of sandstone loom over the arid valley of Wadi Musa like giant handfuls of sun-baked clay. But even in this parched landscape, there are places where the sun casts no light.

Walls 200m high keep the Siq permanently cast in shadow  - it's as though the long, narrow canyon passes through the dark heart of the mountain itself. Utterly silent at dawn, there is not even a bird's chirrup to accompany solitary footsteps along its patchwork floor of rock and sand.

'Atlantis in the Sand': Unlocking the Mysteries of Petra

The ruins of the ancient city of Petra lay hidden until 1812, when a Swiss explorer stumbled upon them in modern-day Jordan. Two centuries later, a new exhibition in Basel brings together some 150 artifacts that shed light on how this mysterious culture of spice traders carved a luxurious oasis into the rocks of the desert.

In the stifling heat, the intruder squeezed his way through the Siq, a narrow gorge flanked by steep rock walls. The man walked through the dark gorge for 1.2 kilometers (0.75 miles). Suddenly, he laid eyes on a magnificent scene.