Barchan dune, 275 square miles of gypsum sand, White Sands National Monument, New Mexico, United States of America (U.S.A.), North America

Wind swept barkhan sand dunes on the barrier island of Isla Magdalena, Baja California Sur, Mexico, North America

Wind swept barkhan sand dunes on the barrier island of Isla Magdalena, Baja California Sur, Mexico, North America

Coyote tracks in the barkhan sand dunes on the barrier island of Isla Magdalena, Baja California Sur, Mexico, North America

Wind swept barkhan sand dunes on the barrier island of Isla Magdalena, Baja California Sur, Mexico, North America

The singing dune in the national park Altyn Emel, Kazakhstan

Namibia, Namib desert, Travelers hike up a 500ft dune ridge on a massive dune deep in the Namib desert near the access point of Sossusvlei.