The Hills of Mars (Saudi Arabia)

Madakhil Camp, Madain Saleh, Kingdom of Saudi Arabia.

In the high-sandstone cliffs of Al-Hajar there are slot canyons more spectacular than anything in the American Southwest. This is part of the UNESCO Cultural Heritage Site at Madain Saleh, featuring enormous tombs reminiscent of Petra in Jordan, which makes sense as they were connected to the same Nabatean empire. Imagine Petra without the tourist hordes, but instead a surfeit of buttes, mesas, spires, slot canyons and phantasmagoric formations that make Monument Valley look like facial pimples, and you have a picture of what this place offers.

Video Credit: Khalel of Arnawa Tours