Gruta do Carvão
Lava caves have been represented in Azorean literature ever since the 16th century, by historian Gaspar Frutuoso, and from the 19th century on by different national and international authors and experts.
Gruta do Carvão (or Charcoal Cave) is one of the most important volcanic cavities in the Island of São Miguel. It was classified as a Natural Monument of the Azores by the Regional Government in May 2005.
In April 2007 it started to welcome visits from schools and organized groups, and the general public the following August. It’s possible to visit one of the sections of the cave upstream with the length from 200 m to 800 m (656 to 2.624 feet) by appointment only. The Cave has a Visitors’ Center.