Raufarhólshellir () is the fourth-longest

lava tube A lava tube, more rarely called a pyroduct, is a 'roofed conduit through which molten lava travels away from its vent'. If lava in the tube drains out, it will leave an empty cave. Lava tubes are common in low-viscosity volcanic systems. La ...

Iceland Iceland is a Nordic countries, Nordic island country between the Atlantic Ocean, North Atlantic and Arctic Oceans, on the Mid-Atlantic Ridge between North America and Europe. It is culturally and politically linked with Europe and is the regi ...

. The cave's proximity to

Reykjavík Reykjavík is the Capital city, capital and largest city in Iceland. It is located in southwestern Iceland on the southern shore of Faxaflói, the Faxaflói Bay. With a latitude of 64°08′ N, the city is List of northernmost items, the worl ...

made it popular with visitors, who caused damage to the cave. In late 2016 the cave was closed to the public to clear accumulated garbage and install lighting and a walkway to part of the cave. The cave reopened for guided tours the following year.

Description

Raufarhólshellir is the fourth-longest lava tube in Iceland, at long, with a typical height of at least and width up to . The cave has multiple skylights, or holes in the ceiling, under which snow accumulates. Iceland Route 39 crosses over the cave at a point where it is about 15 meters in diameter. The cave hosts

microbial mats A microbial mat is a multi-layered sheet or biofilm of microbial colony (biology), colonies, composed of mainly bacteria and/or archaea. Microbial mats grow at interface (chemistry), interfaces between different types of material, mostly on submer ...

containing a variety of microorganisms, including

actinomycetota The Actinomycetota (or Actinobacteria) are a diverse phylum of Gram-positive bacteria with high GC content. They can be terrestrial or aquatic. They are of great importance to land flora because of their contributions to soil systems. In soil t ...

and

acidobacteriota Acidobacteriota is a phylum of Gram-negative bacteria. Its members are physiologically diverse and ubiquitous, especially in soils, but are under-represented in culture. Description Members of this phylum are physiologically diverse, and can be ...

. The land containing the cave is owned by the

Seventh-day Adventist Church The Seventh-day Adventist Church (SDA) is an Adventist Protestant Christian denomination which is distinguished by its observance of Saturday, the seventh day of the week in the Christian (Gregorian) and the Hebrew calendar, as the Sa ...

and rented to a company that operates the guided tours.

History

Raufarhólshellir formed 5600 years ago, based on

carbon dating Radiocarbon dating (also referred to as carbon dating or carbon-14 dating) is a method for determining the age of an object containing organic material by using the properties of radiocarbon, a radioactive isotope of carbon. The method was ...

. The source of the lava flow that created the tube is uphill from the cave and was part of the Leitahraun eruption. An expedition in 1971 by the

Shepton Mallet Shepton Mallet is a market town and civil parishes in England, civil parish in Somerset, England, some southwest of Bath, Somerset, Bath, south of Bristol and east of Wells, Somerset, Wells. It had an estimated population of 10,810 in 2019. ...

Caving Club was one of the first systematic explorations of caves in Iceland. Given its proximity to

, it is popular with visitors. Over 20,000 people visited the cave in 2015. The cave was also used as a

filming location A filming location is a place where some or all of a film or television series is produced, instead of or in addition to using sets constructed on a movie studio backlot or soundstage. In filmmaking, a location is any place where a film crew wi ...

for the 2014 film ''Noah'' and the series ''

Sense8 ''Sense8'' () is an American science fiction drama television series created by Lana and Lilly Wachowski and J. Michael Straczynski for Netflix. The production companies behind ''Sense8'' included the Wachowskis' Anarchos Productions (replac ...

''. Prior to 2016, it was freely open to the public, but it closed late that year due to concerns with garbage accumulation, damage to the cave, and the cost of rescuing visitors. Nearly all of the fragile lava straws had been destroyed by visitors. The cave reopened in mid-2017 after a renovation in which walking decks and lighting was added to the part of the cave nearest the opening, and the removal of several metric tons of trash. The infrastructure improvements were constructed in a way so as not to damage the cave. After the renovation, the cave can only be visited by guided tour. In June 2017, two concerts were held in the cave as part of the Secret Solstice music festival, which included a performance by

Helgi Björnsson Helgi Björnsson (born 10 July 1958), often referred to as Helgi Björns, is an Icelandic actor and pop/rock musician. He has released several albums with his own band Helgi Björns Og Reiðmenn Vindanna. He was also a lead vocalist for the Icela ...

, for which only 50 tickets were available.

References

{{WikidataCoord Lava tubes Caves of Iceland Ice caves