In the eyes of the miners who discovered it in 1952, during the excavation of a well, it must have seemed like an apparition. It had remained undiscovered until that point in time, hidden in the bowels of the mountain. Indeed, the Grotta di Santa Barbara is one of the oldest in the world, certainly the oldest in Italy, and a natural wonder at the heart of the San Giovanni mine, in the territory of Iglesias. After a long period of closure, visits resumed in 2016, with scheduled accesses that serve to preserve the grotto like a precious jewel it is.