Gruta das Torres
Gruta das Torres | |
---|---|
Location | Criação Velha, Pico Island, Azores |
Coordinates | 38°29′39.48″N 28°30′8.64″W / 38.4943000°N 28.5024000°W |
Discovery | 1990 |
Geology | Lava tube |
Entrances | Two |
Difficulty | Easy |
Access | Public |
Gruta das Torres (
The cave's uniqueness lies in its impressive drainage pattern, which can be shown by the presence of more than seven layers on the walls, with lateral benches and three cornices.
Discovery
Gruta das Torres doesn't have a known date of discovery but the first scientific exploration was in 1990. Between March 28 and April 23, 1991, a "three dimensional braided system" was documented by a team of
Geography
The Gruta das Torres is located on the lower western slope of Mount Pico, located in the parish of
Formation
The Gruta das Torres is located on the slope of Pico, further down than Furna de Frei Matias, a large cave inside Pico's cone.[14] The largest lava tube, cited by various sources to either be the longest or second longest in Azores[7] formed by a volcanic eruption originating in Cabeço Bravo. The main part of the tunnel is fairly large with a height of 15 metres in places, although the top side of the tunnel is very small.[7]
The lava tunnel is at a ten-minute walking distance to the south of Madelena. A signpost near Criacao Vella directs to the Grutas Das Torres. The cave has two entrances. The first entrance is open to the sky or a day lighted roof at one end of the tunnel. The other entry is a tunnel cavern opening which is inferred to have been formed due a slump in the roof. The tunnel has clear pāhoehoe lava in some reaches while in some other reaches the roof has collapsed with large lava blocking the tunnel route making access hazardous and narrow. Lava gutters are also seen. A number of secondary tunnels also have impressive geological formations.
The liquid lava that dripped from the roof of Gruta das Torres has formed into picturesque stalactite and stalagmite and also in several other formations and shapes. Inside the tunnel, it is humid as water drips from the roof and a constant temperature of 16 °C (61 °F) is recorded throughout the year. However, the entrance has a slightly higher temperature.[3] The total drop is approximately 200 m (660 ft).[10]
The tunnels formed within a pāhoehoe type lava flow. The top of the flow cooled against the air and formed a solid crust, while beneath it the liquid lava continued to move. As the amount of liquid lava passing through them decreased, the tunnels emptied.[3] Silica oxide is also seen in walls of the cave in some stretches of the cave.[4] At the main entrance, after passing through the ‘Algar da Ponte’ ("Algar Bridge"),[10] there is an avenue of trees. Some forms of plant life like ferns, mosses and lichens are also noted at the portal, floor and walls of the cave opening.
Deep inside, in the darker regions of the cave,
UNESCO Heritage List
Considering the large number of caves found in the Azores archipelago – 271 caves under four categories of rank A, B, C and D, the Government of the Azores initiated a proposal for submission of a few selected caves to
Tourism
The first 450 metres (1,480 ft) are accessible to visitors accompanied by a guide. A visitor centre built in basalt rocks and aesthetically merging with the environment, provides a guided access into the cave. Gruta das Torres has been open to the public since 2005. Visitors are allowed in groups of 15 at a time and each visitor is provided with a protective gear of a helmet fitted with lamps to see the dark interior. At the visitor centre, audiovisual presentations in English and Portuguese give details about the cave.[3] As of 2011, the tours are scheduled for 10:30, 12:00, 13:30, 15:00 and 16:30 for the months of higher visitation (15 June to 15 September).
The visitors' support center at the entrance to the cave has innovative architectural features – “a circular sweep and a linear spatial organization – a sequence of programmatic spaces that prepare visitors for the spectacle below.”[6] It was awarded the "European Union Prize for Contemporary Architecture Mies van der Rohe Award 2007", in Barcelona. It was a formal award presented by the European Union, in association with the Mies van der Rohe Foundation.[3][6]
The innovative construction of the visitor center ensures that the cave entrance has full exposure to the skylight.
References
- ^ a b Greg Middleton AZORES – 2004 11th International Symposium on Vulcanospeleology
- ^ a b c d P.A.V.Borges; et al. (1991). "Caves and Pits from the Azores with some comments on their Geological Origin, Distribution and Fauna" (PDF). Gruta das Torres. Volcanospelology. pp. 122, 126, 133–134. Retrieved December 2, 2010.
- ^ ISBN 978-1-84162-328-3. Retrieved December 1, 2010.
- ^ a b "Gruta das Torres in Pico". Visit Portugal. Retrieved December 1, 2010.
- ^ a b "Gruta das Torres". eccn.edu. Archived from the original on March 15, 2012. Retrieved December 2, 2010.
- ^ a b c d e "Gruta das Torres Visitor Centre". Mimoa the Modern architecture. Retrieved December 1, 2010.
- ^ a b c d "Gruta das Torres" (in Portuguese). Montanheiros.com. Archived from the original on January 21, 2011. Retrieved December 4, 2010.
- ^ a b "Most Outstanding Volcanic Caves Of Azores Islands As Potential Geosites Of The "Azores Geopark". Global Geopark.org. Archived from the original on November 30, 2010. Retrieved December 2, 2010.
- ISBN 978-0-393-73271-9.
- ^ a b c "Gruta das Torres". portais.ws (in Portuguese). May 23, 2009. Retrieved 3 December 2010.
- ^ a b "Sami Architectoes Project". SAMI arquitectos. Archived from the original on January 25, 2010. Retrieved December 1, 2010.
- ^ "Gruta das Torres Visitor Centre". Urbarama.com. Retrieved December 2, 2010.
- ^ a b c "Gruta das Torres". Portais. Retrieved December 2, 2010.
- ^ Partridge, Frank (March 4, 2006). "Outdoors in the Azores". The Independent. Retrieved 3 December 2010.
- ^ "Sami Architectoes Project". SAMI arquitectos. Retrieved 2013-01-31.