Naica’s Crystals Cave, maybe the most amazing underground wonder on Earth ... maybe the only way to visit once it is no longer accessible due to the end of mining activities. Giant crystals The ...

In 2000, miners drilling a tunnel into the Naica Mine in Chihuahua ... The key to the formation of the giant crystals lies in ...

A number of crystal-filled caves have been discovered since mining operations began in Naica back in 1974 ... creating the perfect conditions for giant gypsum crystals to form from a mineral ...