One of the world's most spectacular geographical discoveries was the cave of giant crystals with its selenite crystals of a size never seen before. most of them measure six meters in length, with some of them reaching eleven meters. the temperature at this depth varies from 45°C to 50°C, while the percentage of humidity ranges from 90 to 100%, meaning that human beings cannot survive there for longer than two hours.


Tulio Bernabei observing the interior of the
Crystal Cave where temperatures vary from 45°C
to 50°C and humidity is 100%.

View of the inside of the crystal cave in NAICA.

In the year 2000 at -300 m the Crystals’ cave was discovered. This cave is a true wonder of the underground world. It is one of the most spectacular geological and mineralogical discoveries ever made. It contains selenite mega crystals, some 11m in length and one meter thick. These are much larger than any crystals of this type ever found. The walls and particularly the floor of the cave are sprinkled with blocky single crystals that in some cases cluster to form a parallel aggregate.

Giant elongate selenite mega crystals, the biggest ever found on the planet, grow from some of these groups of blocky crystals or directly from the floor, and some criss-cross the cave from side to side. Most of the crystals are 6 meters long but several reach 11 m creating a natural scenario of unparalleled beauty, beyond imagination, an unreal dream world discovered by chance.

“´NAICA PROJECT" has focused its research, image recording and exploration efforts on this place, because of its importance.

The cave’s walls and above all the floor was scattered with isolated crystals in the shape of a "block" that sometimes group together to form parallel aggregates while some cross the cave from side to side.


The cave’s temperature is 50ºC and 100% humidity, where man can survive only a few minutes. It will continue to be explored with new, specially designed gear, which allows the explorer to remain in the cave for almost one hour. The Crystals’ Cave gives us a glimpse into geological time, thanks to new space-age technology.

Exploring teams, film teams and scientists continue to risk their lives at these hellish temperatures, in order to document this gorgeous underground fantasy-land for future generations.