The volcanic phenomenon of Algar do Carvão is located in the heart of the wonderful Terceira Island, Azores Archipelago, in the interior of the Guilherme Moniz Cauldron.

The Algar do Carvão is located in the interior of a sleeping volcano, constituted by a volcanic cone with about 90 meters high, including in its interior a beautiful lake of crystalline peaceful waters at about 100 meters depth.

The Algar do Carvão would have had origin in the great Pico Alto eruption that threw lava into far distance. Afterwards, another basaltic eruption started the process of the formation of another volcano, the Pico do Carvão.

The lava accumulations produces acid lava rivers quite fluid that carbonized the surrounding vegetation.

The access to Algar do Carvão is nowadays eased with the construction of some stairways on its interior, that allow comfortable views over the itinerary the lava river drew, and also the curious volcanic stalactites and stalagmites.