Those brave enough to venture into the heart of Ethiopia’s Danakil Depression encounter a windswept desert, punctuated by caustic salt lakes and scalding geysers. It’s a dangerous place, almost completely devoid of life, and seldom visited—except for the occasional hapless wanderer like this caper white butterfly (Belenois sp.), which fell victim to the heat and toxicity of the Dallol sulfur springs.

Northeast Ethiopia has been an inhospitable place for millions of years due to its overactive geology and harsh climate. Here, diverging tectonic plates tear Earth’s crust apart and bring molten magma and noxious fumes to the surface. Moreover, the annual average air temperature of 35 degrees Celsius (94 degrees Fahrenheit) makes this region one of the hottest places on the planet.

But it hasn’t always been this way; the Danakil Depression was once flooded by a vast inland sea. When the water evaporated, beginning in the Jurassic period, it left behind more than a million tons of salt deposits. Today in Dallol, magma-heated groundwater dissolves these minerals and carries them to the surface. The high temperatures and low humidity cause the water to evaporate, and the salt that remains crystallizes into spectacular flowering formations colored yellow by sulfur, red by iron, and green by mineral- and heat-tolerant microorganisms that live here (the only lifeforms that can withstand the conditions long-term). Scientists studying the origins of life—on Earth and perhaps other planets—hope to learn more about these organisms and how they’ve adapted to the extreme environments here.

When photographer Marcus Westberg set out to capture this unusual world, he knew he’d need to arrive early to avoid the worst of the day’s heat and fumes. “It’s so lethal,” Westberg says, “[the armed military escorts] don’t allow afternoon visits at all.” Threats of the region’s ongoing civil unrest and the risk of a misstep plunging him into the hot springs compounded the challenges of Westberg’s visit. But just after dawn one morning, his efforts were rewarded when he saw a lone, extinguished butterfly, its wings already encased in growing crystals of salt. “We saw no live butterflies, nor any other animals, at Dallol,” he says, “but this crystalized one was nevertheless proof that life does exist here”—albeit briefly in this case.