This story appears in the November 2012 issue of National Geographic magazine. I got my first lesson in the physics of sand dunes in 1998 on an expedition into the Sahara. In order to take aerial ...

Argyilan saw no sign of an opening or even upturned sand, which you’d expect if someone had dug a hole. As for natural cavities, dunes aren’t supposed to have any. Unlike hard rock ...

Wearing a helmet and strapped securely into his four-wheel-drive, Abdelilah al-Rabea tore off across the Saudi desert, kicking up clouds of sand as a crowd of hundreds cheered him on. Every year ...

How can something that is constantly shifting stand up to 750 feet tall? This southwestern park features the largest sand dunes in North America, and the key to their extraordinary height seems to lie ...