Accessible on foot or by tourist train, the largest cave network in Europe has been providing shelter for millennia. The entrance to the cave is by a huge natural porch. The tour starts in a high-ceilinged gallery before moving onto the Carène gallery, depicted by a low ceiling, split down the middle by a flaw. The visit continues through chambers dotted with rimstones and bristling with stalactites, stalagmites, curtains, columns and organs, such as the "white mammoth" and the "witch".