About 20 km from Portoscuso, inside the San Giovanni mine in Iglesias, lies one of Sardinia's most surprising caves. The Grotta di Santa Barbara has no natural entrance: it was discovered by chance in April 1952, when miners digging a gallery broke through the rock into a cavity that had stayed sealed for millions of years. It's named after Saint Barbara, patron saint of miners.
One of Europe's oldest caves
It formed in Lower Cambrian rock around 500 million years old — among the oldest in Italy. Inside, a large ovoid chamber rises over 25 metres and holds stalactites, monumental stalagmites, aragonite columns with blue hues, and dark brown barite crystals unmatched elsewhere in continental Europe for size and quality. The lower part of the cave holds a small underground lake.
How to visit
Because it has no natural entrance, the cave can only be reached through the mine's own tunnels: a short ride on a mine train, then a lift up a mining shaft, and finally a spiral staircase down into the main chamber. Guided tours last about an hour, run on weekends (Saturday and Sunday) with departures at 10:30, 12:00, 14:00, 15:30 and 17:00 — some in English — and need to be booked ahead, either online at iglesiasturismo.it or in person at the tourist office in Piazza Municipio. A full ticket costs €15, with discounts for children, over-65s, groups and pilgrims on the Cammino di Santa Barbara with a credential.
Why it's worth the trip
It's a different kind of outing from the usual day at the beach: a journey underground that tells both the island's geological history and the mining history of Sulcis-Iglesiente. It pairs well with a visit to Porto Flavia or the Laveria Lamarmora, both just minutes away, for a full day dedicated to the mines.
- The temperature inside is a steady 16–18°C year-round: bring a light jacket even in summer.
- Closed, comfortable shoes are a must: the route includes stairs and stretches of bare rock.
- Children need to be able to walk the whole route on their own, or be carried in a child backpack carrier.
- Walking the Cammino di Santa Barbara with a pilgrim's credential gets you a discount on the ticket.
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