Algar do Carvão is a strombolian volcano with two cones (a principal and an accidental one) and is 629 m high. It is composed by a vertical chimney of 45m high and it becomes obliquely wider in its end, with three arched roofs. It ends with a lagoon whose average surface is 400m2 . In its deeper part it is 15m. The walls allow the water infiltration which gives origin to white silica stalagtites and stalagmites. We can also observe black obsidian "volcanic vitrious glaze" (glass). The plant communities of the volcanic chimney have a great diversity of species and some are rare and threathened.
Algar do Carvão is located in Terceira island, in the Azores Archipelago.