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

Erin Argyilan was wrapping up a scientific study of wind speeds on Mount Baldy last year when she saw a circle of beachgoers on their knees halfway up the hulking sand dune. They appeared to be ...

What do you picture when you think of the Sahara? A vast expanse of towering sand dunes? The occasional oasis, perhaps? But mostly, we tend to imagine a very sandy landscape. Turns out ...