Cave of the Crystals. Mexico
This amazing place is known as Cave of the Crystals or Giant Crystal Cave which is located in the south of the State of Chihuahua, Mexico, North America. «Cueva de los Cristales» (Spanish) is located at a depth of almost 300 meters below the surface of Naica.
The cave is a unique natural formation, famous for its huge transparent crystals of selenite. This mineral, structural variety of gypsum, reaches the height of eleven meters. The largest discovered crystal weighs 55 tons. These huge rays disorderly cross space of the cave similar to a maze with length of 27 m and create a fantastic spectacle! These crystals are the largest in the world!
Magmatic funnel which is under the cave gradually heated the groundwater and saturated with minerals. For a long time the grotto was filled with hot solution of minerals. The temperature contributed to the growth of crystals of selenite. It is very hot in here. Temperature in the cavern can rise up to 58 °, while the air humidity reaches 100%. This is a very difficult condition for exploring the cave. Even with special equipment, a person can be in a cave no more than 20 minutes. Therefore, you should be very careful here, because a long stay in the cave can lead to heatstroke or even to lethal outcome (and there were such cases).
For the first time the crystal cave was discovered in 1920. The crystals found at that time reached 2 meters. They were quickly taken away by various Mineralogical Societies, and soon the unique finding was forgotten. The next time this cave was recalled in 2000. Brothers Sanchez, the miners who were digging a new tunnel for the mine complex, discovered another three cavities. Thus, the “moonstone,” as this mineral is also called, attracted attention again. In 2006, a special project was launched, which aim was to protect such a unique natural object from the harmful effects of the environment.
Because of the harsh microclimate (high temperature, humidity and hydrogen sulphide), as well as due to the fragility of crystalline blocks, the entrance for tourists is closed.