It starts in Santadi, known for Carignano wine, for its archaeological heritage and for the caves dug out of the dolomite rocks of Mount Meana. They are still active and each of their rooms has unusual concretions: one boasts the greatest concentration of helictite aragonites in Italy. Along the route, of approximately 500 metres, you can also admire splendid stalactites, stalagmites, flows and ‘straws’. At Christmas, the Organ Room hosts an evocative nativity scene.

Travelling about another fifty kilometres, you will reach the territory of Iglesias, near the Monteponi mine and next to that of San Giovanni. It was a miner who first discovered the ‘oldest’ cave in Italy. The large, 25-metre-high room is dotted with stalactites, making it look almost like a majestic cathedral. You can also admire the honeycomb concretions and the small lake in the lower part. You can get there by local train and lift, along tunnels marked by the daily toil of the miners.

The shortest stretch, which is less than twenty kilometres, allows you to visit one of the only three caves in the world crossed by a road. Just outside Domusnovas, close to the Marganai forest - which is full of abandoned mining plants -, a long and evocative cave appears, the name of which comes from a chapel that is no longer there. Today you can travel along its 850 metres on foot, thus allowing you to admire the details of the limestone basins and the walls covered with stalactites and stalagmites.

The last stretch is 35 kilometres long, concluding the itinerary not far from the captivating temple of Antas. In the territory of Fluminimaggiore, there is a complex that is still ‘alive’, although it emerged 500 million years ago. One room was used as a temple in the Pre-Nuragic age, while the speleological tourist route, between walkways and steps, allows you to admire pillars, crystal ‘trees’, small lakes, cave pearls and aragonites with a very original appearance.