Giant Crystal Cave in Mexico

Cave of the Crystals or Giant Crystal Cave (Spanish: Cueva de los Cristales) is a cave in Naica, Chihuahua, Mexico. The main chamber contains giant selenite crystals, 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. A group of scientists known as the Naica Project have been heavily involved in researching these caverns.

Video by BBC