Algar do Carvão
Portugal · Europe
About
The Algar do Carvão (Cavern of Coal) is an ancient lava tube or volcanic vent located in the central part of the island of Terceira in the Portuguese archipelago of the Azores. It lies within the civil parish of Porto Judeu in the municipality of Angra do Heroísmo.
Adapted from Wikipedia (CC BY-SA)。Photography via Wikimedia Commons.