Ugab River #

Image courtesy of USGS., under PD

Shown in this false-color satellite image, the subterranean waters underlying this ephemeral river are shallow enough in places to fill hollows and sustain wildlife populations that include the rare desert elephant and the largest free population of black rhino.

Pink-granite inselbergs, islands of rock left behind after volcanic activity, form bizarre sculptures in the sandy riverbed. Some, known as "petrified ghosts," are eerie hollow structures, carved by erosion.