Naica Crystal Cave
"Cave of the Crystals or Giant Crystal Cave (Spanish: Cueva de los Cristales) is a cave connected to the Naica Mine 300 metres (980 ft) deep in 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 11 m (36 ft) in length, 4 m (13 ft) in diameter and 55 tons in weight. The cave is 27 m (89 ft) in length and 9 m (30 ft) in width. The cave is extremely hot with air temperatures reaching up to 58 °C (136 °F) with 90 to 100 percent humidity. The cave is relatively unexplored due to the extreme temperatures and high humidity. Without proper protection people can only endure approximately ten minutes of exposure at a time. . . . . . "
"A team of international scientists explore a Mexican cave filled with giant crystals. With temperatures near 120 degrees Fahrenheit (48.8 Celsius), and over 80 per cent humidity, the cave is one of the deadliest environments on earth. Without specialized suits and equipment, the scientists would die in minutes. Their mission: to unlock the secrets of the mysterious ancient crystals, some of the largest ever discovered."
Naica Crystal Cave - Mexico 1/5