Danakil Depression, Geological depression in Afar Region, Ethiopia.

This geological depression stretches 200 kilometers long and 50 kilometers wide, sitting partially 410 feet (125 meters) below sea level. The landscape encompasses salt lakes, lava lakes, active volcanoes and acidic springs whose mineral deposits create bright yellow, green and red colorations.

Paleoanthropologists discovered the Lucy fossil here in 1974, a 3.2 million year old Australopithecus afarensis specimen that established the region as a significant site for human evolution research. Tectonic activity at the junction of three continental plates has been reshaping this depression for millions of years.

The depression lies in Afar territory, and its name comes from the Afar people who live there; the Russian name Afar and the older Dancalia both refer to them. The salt plain around Lake Karum still yields salt, and the brine left after seawater evaporated there long ago is what the miners cut. Dallol, a salt dome built by hot springs, is uninhabited apart from a few half-abandoned dwellings.

Tours depart from Mekele between September and May when temperatures drop to 95 degrees Fahrenheit (35 degrees Celsius) rather than the extreme 122 degrees Fahrenheit (50 degrees Celsius) during summer months. Visitors require four-wheel drive vehicles, armed guides per regional regulations and must bring adequate water and sun protection.

Dallol is a salt volcano, not an ordinary crater: magmatic fluids rise through the evaporite deposits, dissolving them, and escape at the surface extremely hot, salty and acidic. Oxidation of dissolved salts and iron-chlorine sulfates, together with evaporation, builds the yellow, red and green mineral shapes around the springs. Biologists searching for extremophiles found microbes in most of Dallol's ponds but not beside the hot chimneys where the fluids emerge.