The Sun scorches the cracked earth, a wavering mirage confuses the eye, and dry air and dust suck the moisture from your mouth and eyes. Ethiopia's Danakil Depression is one of the hottest, driest and lowest places on the planet.

The area is located in the Afar Region of north-east Ethiopia near the border with Eritrea. The climate here can only be described as cruel. But against all odds, people do live here. The Afar people call it their home.

The Danakil Depression is a contender for the hottest place on Earth, at least if you measure the average year-round temperature (reportedly 34.4C) rather than focusing on isolated bursts of extreme heat.

Worse, it only receives 100 to 200mm of rainfall per year and it is also one of the lowest places on the planet, at 410ft (125m) below sea level.

Combined, these factors make it one of the most inhospitable environments in the world.

If the climate was not enough, the region's energetic geology makes it look like an alien land. It was the strange geological phenomena that I was there to see.

Walking around the area you feel like you are on another planet. There are volcanoes with bubbling lava lakes, multi-coloured hydrothermal fields, and great salt pans that dazzle the eyes.

The Danakil Depression is the northern part of the Afar Triangle, a geological depression caused by the Afar Triple Junction: a place where three tectonic plates join.

The Depression overlaps the borders of Eritrea, Djibouti and the entire Afar Region of Ethiopia. It is part of the great East African Rift Valley.

A rift valley is where the Earth's tectonic plates move apart, creating new crust. Here the plates are moving apart along three deep rifts at a rate of 1-2cm per year.

This is why you see lava lakes lighting up the night sky, faults and fissures scarring the landscape, and steaming hot springs and geysers.

One day millions of years into the future, the plates will have moved apart so much that the salty waters of the Red Sea will spill over, creating a new ocean and drowning this strange landscape forever. Then, the Danakil Depression will be the birthplace of a new ocean.

In 1974, Donald Johanson and colleagues found the celebrated Australopithecus fossil known as "Lucy" in the region.

Many other fossils of ancient hominins have been uncovered here, prompting some palaeontologists to propose that this area is where our species first evolved. As a result, it is often referred to as the "cradle of humanity".

The area is also used to investigate how life might evolve on other planets.

The hot springs in the Danakil Depression are home to microorganisms called extremophiles, which as the name suggests live in extreme conditions.

Microbes like this are of special interest to astrobiologists, as they could help to explain how extraterrestrial life could arise.

Exploring this strange region means driving for hours on bumpy, dusty dirt roads, starting from a town called Mekele. You drive down through Ethiopia's highlands into this low-lying desert.

You would not think anyone could live here, but the Afar people have made it their home. While we sweltered in the hot sun longing for water, they looked remarkably cool and relaxed.

This is evolution at work. Their bodies are adapted to the heat and dryness, so they need far less food and water than most other people.

When we stopped for a much-needed refreshment break, a lonely figure could be seen walking towards us through the heat mirage. It was a young Afar man, and as he got closer it became clear that he was not alone. The mirage had hidden a long line of camels behind him, all carrying salt to market.

Salt is like money to the Afar. They cut slabs of salt from the vast salt pans and take them to market in Mekele on the backs of camels and donkeys. It is about a week's walk, often only with a small loaf of bread and bottle of water.

One day I was watching an Afar man cut salt from a lakebed. He noticed how hot I was and offered me some bread and water. I was struggling in the heat with my big camera and several litres of water in my backpack, and there he was with little more than the clothes on his back.

I accepted the bread and then refilled his water bottle with my water. He was very grateful for the water, and I was left humbled by a man who had so little yet had offered me his last food and water.

The Afar live a basic life. They are nomadic, living in moveable wooden huts, and look after small herds of cattle, goat, donkeys and camels.

The one river in the region, the Awash is surrounded by a narrow fertile belt, which gives life to the Afar and their herds.

The Awash is one of the world's most unique rivers, because it never reaches the sea, flowing from the Ethiopian highlands down into lakes in the Danakil Depression. The intense heat there means that all the water evaporates, leaving behind the great salt pans.

Although the Depression is a dry and barren place, the river still brings life, both in the water itself and the valuable salt that it carries.

This moon-like landscape is harsh, but it has brought us wonders beyond belief: from fascinating volcanic landscapes to clues to extraterrestrial life, and possibly the dawn of humanity.

Follow Vivien Cumming's adventures on instagram and twitter: @drvivcumming

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