green vegetation of ferns in the opening wall of the volcanic cone of algar de carvão, terceira - azores portugal

adventure algar angra attraction azores açores carvao carvão cave cavern cone covered crater destination entrance environment europe extinct ferns flora focus foliage geological green grottoes heroismo humidity inside interior island judeu landscape lava light moisture moss mossy natural opening outside porto portugal portuguese selective sky terceira tourism touristic travel tree tube vegetation volcanic volcano wall walls