Cave of the Crystals in Mexico
Where People are tiny. The ‘Cave of the Crystals’ lies 120 meters below the ‘Cave of Swords’
Cave of the Crystals or Giant Crystal Cave (Cueva de los Cristales) is a cave connected to the Naica Mine 300 metres (980 ft) below the surface in Naica, Chihuahua, Mexico. (thahanks Beja von Bis)
The main chamber contains giant selenite crystals (gypsum, CaSO4·2 H2O), some of the largest natural crystals ever found.The cave’s largest crystal found to date is 12 m (39 ft) in length, 4 m (13 ft) in diameter and 55 tons in weight. The cave is extremely hot, with air temperatures reaching up to 58 °C (136 °F) with 90 to 99 percent humidity. The cave is relatively unexplored due to these factors. Without proper protection, people can only endure approximately ten minutes of exposure at a time.
The cave was discovered by the brothers Eloy and Javier Delgado.
A group of scientists known as the Naica Project have been heavily involved in researching these caverns. (knowledge via wikipedia)