A deadly cavern in Chihuahua, Mexico, dubbed ‘the Sistine Chapel of crystals’, is buried almost 1,000 feet (300 meters) beneath Earth’s surface and contains giant gypsum crystal beams up to 11 metres long.

The cave system is only reachable from a lead, zinc and silver mine in Naica, 105 kilometres southeast of Chihuahua City.  The mine was flooded almost 10 years ago after workers accidentally broke into an aquifer, but the Cave of Crystals lies nearer the surface and the floodwater hasn’t reached it yet.

The flooded mine is associated with pre-Columbian ochre mining, which is currently being investigated by underwater archaeologists.