Crystal Palace 1km beneath Earth..

Next holiday destination...1km below the Chihuanhuan Desert, Mexico.


Deep inside Naica mountain, the Cave of Crystals is a horseshoe-shaped cavity in limestone rock about 10 meters wide and 30 meters long. Ambient temperatures hover around 60c.

Volcanic activity that began about 26 million years ago created Naica mountain and filled it with high-temperature anhydrite gypsum (giant shards of which are pictured above).

When magma underneath the mountain cooled and the temperature dropped, the anhydrite began to dissolve. The anhydrite slowly enriched the waters with sulfate and calcium molecules, which for millions of years have been deposited in the caves in the form of huge selenite gypsum crystals.