Nearly 1,000 feet (305 meters) beneath Mexico's Naica silver mine you'll find a chamber of unearthly wonder. Here in Cueva de los Cristales (the Cave of Crystals), 36-foot (11-meter) obelisks of solid crystal lay heaped about like fallen pillars in a dilapidated temple.
This subterranean forest of wonders boasts the largest known gypsums (soft minerals made of hydrate calcium sulfate) on Earth. For roughly half a million years, the hidden chamber was nothing short of a crystal incubator. For starters, nearby magma deposits heat the cavern to temperatures of up to 112 degrees Fahrenheit (44 degrees Celsius). And to top things off, the entire space was flooded with mineral-rich waters up until very recently.
The chamber was discovered in 2000, after mining operations pumped it dry. Today, only a few visitors risk heatstroke to witness the crystals' beauty firsthand.