
Algar do Carvao or Cavern of Coal in Terceira Island, Azores, Portugal. It 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
Algar do Carvao or Cavern of Coal in Terceira Island, Azores, Portugal. It 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