Cave Gruta das Torres - a cave with lava tubes, a geological formation of volcanic origin. Lava tubes are formed as a result of uneven cooling of a hot volcanic magma flows in contact with the air it.

The cave is located outside the area Kriasan Vella, municipality of Madalena, in the western part of the island of Pico, and is a group of interconnected lava tubes, the width which ranges from 0, 5 m to 22 m., Height - 1, 2 m to 15 m. It is a cave at an altitude of 300 meters. The length of it is about about 5 km 2, and the cave Gruta das Torres is considered the longest lava cave in the Azores.

The exact date of the opening of the cave is not known, but the first scientific expedition was sent there in 1990. The uniqueness of the cave is its impressive size of the drainage network, which is seen by more than seven layers on the cave walls with lateral and three cornices.

Gruta das Torres - one of the 17 caves on the island of Pico, which is included in UNESCO World Heritage List as part of the phenomenon of volcanic origin in the mountains of the Azores. In addition, the Gruta das Torres is one of 28 caves discovered on the island of Pico, the amount of which is considered to be large enough. The cave is ranked eighth in size among the rest of the crater caves on the island, which, it should be noted, has the highest number of caves than any other island in the Azores archipelago.

Open to visitors Gruta das Torres began in 2005. It organizes guided tours. The first 450 meters of the group passes a guide. The group recruited no more than 15 people, and each visitor is provided with the protective gear that includes a helmet, equipped with lights to help see in the dark. At the entrance to the cave was built visitor center, where there is an audience, in which you can see a movie of this natural phenomenon.