The Cave of Crystals

The Chihuahua, Mexico, region has been a mining hotspot because of its metal reserves since the early 19th century, and the Cave of Crystals was initially found in 1910 during a mining dig. It was known as one of the bizarre geological features of the Earth since a long time ago and was the Cave of Swords back then because it contained enormous, three-foot-long gypsum crystals that weren't found anyplace else at the time.

But in 2000, a team of miners discovered a different, much larger network of caverns close by. Gypsum crystals in this location can grow up to 40 feet long and three feet wide, and people have no idea if there are any deeper caves with crystals that are even larger. Due to the intense seismic activity in the area, these crystals only formed after countless years of mineral-rich waters seeping into the caves. This enables the accumulation of calcium sulfate, which then combines with different elements to generate a variety of minerals, including gypsum. The caverns draw specialists from all over the world, including crystallographers and geologists, due to their numerous distinctive geological features.

Location: Naica, Chih., Mexico