Star dunes - sometimes called pyramid dunes - stand out among sand dunes for their towering height and eye-catching form.

this issue). Sand deposition, accretion, and erosion within the coastal environment result in the development of a variety of dune morphologies; however, a general classification into primary and ...

There are two creeks at Great Sand Dunes. Medano Creek is closest to the Visitor Center and the most popular with visitors. Depending on the conditions, visitors can surf, wade, raft, or just dip ...

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 ...