Home / Azores Geopark / Caldeira e Furna do Enxofre - Geosite, Caldeira da Graciosa
"Caldeira" is a collapse caldera emplaced on the top of the polygenetic volcano that occupies the SE sector of Graciosa island. Inside the depression there are two hydromagmatic cones, a swampy area and a volcanic cave "Furna do Enxofre". With a maximum length of 194 m, this 40 m high dome-shaped volcanic cave is unique worldwide, enclosing a lake and a fumarolic field that includes a mud-poll fumarole and soil diffuse degassing.