Furna do Enxofre

Sulfur Cave

Useful Information

Location: Near Canada Longa.
Follow road to the southeast, signposted Caldeira, through tunnel to the end of the road. Nearest bus station at Canada Longa, 40 min walk.
Open: Winter Mon-Fri 9:30-12:30, 13:30-16:30.
Summer Mon-Fri, 9-12:30, 14-17:30, Sat, Sun 11-16. [1998]
Fee: Adults 100 Esc. [1998]
Classification: volcanic cave
Light: LightIncandescent Electric Light System
Guided tours:
Bibliography: Rosalina Gabriel, Fernando Pereira, Sandra Câmara, Nídia Homem, Eva Sousa, Maria Irene Henriques (2006): Bryophytes of Lava Tubes and Volcanic Pits from Graciosa Island (Azores, Portugal), AMCS Bulletin 19 / SMES Boletín 7 - 2006 Book online
As far as we know this information was accurate when it was published (see years in brackets), but may have changed since then.
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1898 visited by the oceanographer and geologist Prince Albert of Monaco.
1939 staircase into the cave built.


The caldera is the main sight on Graciosa, the second smallest island of the Azores. And this because of the Furna do Enxofre, a big cave inside the crater of an volcano. The caldera is located at the south east end of the island. It has a diameter of 1,200 m, numerous cave, of which the Furna do Enxofre is the biggest. There are numerous thermal springs and solfatares, some in the cave.

The road from Canada Longa goes through a tunnel into the crater to the cave entrance. The caldera also contains a picknick and barbecue area. The Furna is located at the end of the road, in the south eastern corner of the caldera, just below the highest point of the rim (402 m asl).

From the parking lot a winding stairway leads 100 m down into the cavern, buit of local rocks at the cavern wall. You reach a huge dome, 130 m in diameter, 80 m high with the huge opening on one side where you came down. It is recommended to visit the cave betwen 11 and 14, as the sunlight shines through the entrance shaft at this time, and lights up the whole dome.

This cave is known for some time, and has a certain reputation among geologists. The oceanographer and geologist Prince Albert of Monaco visited the cave in 1898. He sailed across the Atlantic ocean, just to see this cave. And to get in he had to climb down the 100 m over a rope ladder. The staircase of today was built much later.

The staircase was built in 1939 and it allowed the farmers of the area to fetch water in the cave lake for their livestock. The staircase was very expensive, it costed 14,000 Escudos.

The source of the water was the Styx lake, impressive 130 m in diameter and 15 m deep. Later, when the cave was used as a show cave, a wooden boat allowed a fantastic boat trip on the lake. But today the boat lies on the shore and is leaking. The water level of the lake sinks continuously and hot steam and sulfuric exhalations make it very dangerous. Today the lake is enclosed at some distance. Still, a visit to the cave is worthwhile.

A last word: do not mix up the Furna do Enxofre with the Furnas do Enxofre on Terceira. The later are sulfuric springs without any cave.