Algar do Carvão

On the island of Terceira, the Algar do Carvão is a volcanic chimney that visitors can enter, descending into a vast underground space. Its walls are hung with rare stalactites of silica, and at the bottom lies a small lake, making it one of the most unusual natural monuments in the Azores.

Inside a volcano

The Algar is the vent of a volcano that erupted thousands of years ago, leaving a vertical chimney more than 90 metres deep. Unlike the lava tubes found elsewhere in the Azores, it can be visited from the inside, with stairways and paths leading down to the lake. The silica stalactites that hang from the roof are among the few of their kind in the world.

What to see

• The descent into the volcanic chimney.
• The silica stalactites and the colours of the rock.
• The underground lake at the bottom of the Algar.
• The surrounding volcanic landscape, including the nearby Gruta do Natal.

Visiting the Algar

The Algar do Carvão is in the centre of Terceira, near Angra do Heroísmo. Because it is a protected monument, visits may be subject to opening times and conditions; check the official information before your visit.

Visitor information: visitazores.com.

Image credit: Algar do Carvão, Terceira, by Diego Delso, CC BY-SA 4.0, via Wikimedia Commons.