Barrier islands are found along the edge of every continent except Antarctica, and in 2011 scientists and naturalists are still finding new ones, including this chain along the equatorial coast of Brazil.
This astronaut photograph shows classic large and small sand masses of the central Sahara Desert, where wind is a more powerful land-shaping agent than water.
On most summer days, a trip to North Carolina’s Outer Banks means a peaceful day at the beach, but there is evidence all around that this beach is not always so serene.