Danakil Depression

The Danakil Depression is a vast area of volcanic terrain in north-eastern Ethiopia where the Earth's crust is being pulled apart at a rate of approximately two centimetres per year along the African Rift Valley, and the surface has dropped to between 100 and 125 metres below sea level, making it one of the lowest points on the African continent and one of the most geologically active landscapes on the planet.

The average annual temperature recorded at Dallol, the former mining settlement in the northern depression, is 34.4 degrees Celsius — the highest average annual temperature ever recorded at a permanent weather station on Earth — and the area is also one of the driest, receiving less than 100 millimetres of rain per year. The combination of extreme heat, very low elevation and the presence of the rift zone produces a landscape that resembles nothing else on Earth: vast salt flats, acid pools that bubble with sulfuric acid, and volcanic vents that emit chlorine and sulphur gases that react with the moisture in the air to produce vivid yellow and green deposits.

The acid pools of Dallol have pH values measured at below zero, and the salt formations, iron deposits and sulfur crusts create surreal yellow, green and turquoise formations that look like a landscape from another planet. These formations have made the site a subject of scientific study for extremophile microbiology, as scientists investigate the microbial life forms that survive in conditions previously thought to be incompatible with biological processes.

Erta Ale, a shield volcano in the southern Danakil, contains one of the world's only six known persistent lava lakes, and its summit crater has been continuously active with lava fountaining episodes for more than fifty years, creating a glowing orange-red disc visible from the surrounding hilltops at night. The Afar people have lived in this harsh environment for centuries, mining salt from the depression using traditional hand tools and loading the slabs onto camel trains that still cross the desert to the markets of Berahile, a trade route that has remained essentially unchanged for generations.

The Danakil is considered one of the most physically demanding tourist environments in the world, and visitors require an experienced guide, a properly equipped expedition vehicle with spare tyres and recovery equipment, and awareness that no mobile phone coverage and minimal infrastructure exist across the entire depression. The Ethiopian Tourist Organisation has listed the Danakil as a priority development zone, and improved access roads and new eco-lodges near Erta Ale are under discussion, though the fundamental challenges of extreme heat and logistical remoteness remain unchanged.

The most extreme volcanic landscape in Africa and one of the most alien-seeming environments on Earth, with salt flats, acid pools and an active lava lake.

Erta Ale contains one of only six persistent lava lakes in the world, offering a rare opportunity to observe continuous volcanic activity at close range.

The Afar salt trade, in which camel trains carry salt slabs across the desert to market, offers a rare window into a traditional economy that has persisted for centuries.