Camels

A man walks on a sand dune with his camels in Mhamid el-Ghizlane, in the Moroccan southern Sahara desert.

Fadel Senna/AFP

A man walks with his camels in M’hamid el-Ghizlane, in the Moroccan southern Sahara desert.

A man leads camels at the edge of the Taklamakan Desert in Xinjiang Uighur Autonomous Region...A man leads camels at the edge of the Taklamakan Desert in Xinjiang Uighur Autonomous Region, October 29, 2013. Picture taken October 29, 2013. REUTERS/China Daily (CHINA - Tags: SOCIETY ENVIRONMENT ANIMALS TPX IMAGES OF THE DAY)

China Daily/Reuters

Camels are led across the Taklamakan Desert in Xinjiang Uighur Autonomous Region.

A man walks on sulphur and mineral salt formations near Dallol in the Danakil Depression...A man walks on sulphur and mineral salt formations near Dallol in the Danakil Depression, northern Ethiopia April 22, 2013. The Danakil Depression in Ethiopia is one of the hottest and harshest environments on earth, with an average annual temperature of 94 degrees Fahrenheit (34.4 Celsius). For centuries, merchants have travelled there with caravans of camels to collect salt from the surface of the vast desert basin. The mineral is extracted and shaped into slabs, then loaded onto the animals before being transported back across the desert so that it can be sold around the country. Picture taken April 22, 2013. REUTERS/Siegfried Modola (ETHIOPIA - Tags: BUSINESS SOCIETY TPX IMAGES OF THE DAY)     ATTENTION EDITORS: PICTURE 2 OF 30 FOR PACKAGE 'ETHIOPIA'S ANCIENT SALT TRAIL'  SEARCH 'DANAKIL DEPRESSION' FOR ALL

Reuters

The Danakil Depression in Ethiopia is one of the hottest and harshest environments on earth, with an average annual temperature of 94 degrees Fahrenheit (34.4 Celsius). For centuries, merchants have traveled there with caravans of camels to collect salt from the surface of the vast desert basin. The mineral is extracted and shaped into slabs, then loaded onto the animals before being transported back across the desert so that it can be sold around the country. Read more