Awesome. Simply breathtaking.
I want to catch this series!
Click the link to view, as it's on the BBC website.
BBC News - A rare glimpse of the cave of crystals
Mexico's Cave of Crystals stunned geologists when it was first discovered in 2000. The underground chamber contains some of the largest natural crystals ever found - some of the selenite structures have grown to more than 10m long. Professor Iain Stewart got a rare glimpse of the subterranean spectacle while filming for the new BBC series How the Earth Made Us.