The geothermal area of Dallol in the Denakil Desert is one of the most exotic landscapes in the world. The water fizzing out of the hot springs is bright green and very clear. It runs off the Ethiopian Highlands and washes deep gullies into the thick salt crust before spreading out and evaporating. The salt was deposited when the Denakil Desert was still an arm of the nearby Red Sea. (aerial view)