Furna do Enxofre

The great volcanic cave of Graciosa, with its lake under the dome of rock.

In the centre of Graciosa, inside the great caldeira of the island, the Furna do Enxofre opens in the rock: a volcanic cavern of enormous height where a lake of green water lies under a perfect dome of stone. It is one of the great natural monuments of the Azores — a place of geology in its purest form, reached by descending a spiral tower into the heart of an ancient volcano.

The cave

The furna was formed by the collapse of a volcanic chamber, in the heart of the caldeira that dominates the island. Inside, the hall rises like the nave of a cathedral, with the skylight of the entrance above and the lake — fed by rain and fumaroles — in the depths; the air carries the smell of sulphur that gave the cave its name. The visit descends by a modern access tower, with a spiral staircase, to the floor of the cavern and its viewpoints over the water.

What to see

The great volcanic hall and its dome of rock.
The lake and the fumaroles of the cave floor.
The descent by the spiral staircase of the access tower.
The caldeira of Graciosa and its landscapes around the entrance.

Visiting

The cave is in the centre of Graciosa, reached by road from Santa Cruz across the caldeira; the descent is made by the access tower, with stairs and a damp atmosphere, so comfortable shoes and a jacket are recommended. The opening times, tickets and conditions of the visit follow the official information of the municipality and of the island’s tourism sources.