Raufarhólshellir () is the fourth-longest

lava tube A lava tube, or pyroduct, is a natural conduit formed by flowing lava from a volcanic vent that moves beneath the hardened surface of a lava flow. If lava in the tube empties, it will leave a cave. Formation A lava tube is a type of lava ca ...

Iceland Iceland ( is, Ísland; ) is a Nordic island country in the North Atlantic Ocean and in the Arctic Ocean. Iceland is the most sparsely populated country in Europe. Iceland's capital and largest city is Reykjavík, which (along with its s ...

. The cave's proximity to Reykjavík 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 containing a variety of microorganisms, including actinomycetota 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 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 Sabbath, and ...

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 dev ...

. 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 parish in the Mendip District of Somerset, England, some south-west of Bath, south of Bristol and east of Wells. It had an estimated population of 10,810 in 2019. Mendip District Council is based t ...

Caving Club was one of the first systematic explorations of caves in Iceland. Given its proximity to Reykjavík, 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, in addition to or instead of using sets constructed on a movie studio backlot or soundstage. In filmmaking, a location is any place where a film crew wil ...

for the 2014 film ''Noah'' and the series '' Sense8''. 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