Useful Information

Location: West coast of the island of Hestur. Boats start at Gamlarætt on Streymoy.
(61.9357574, -6.8778601)
Open: no restrictions.
rib62: MAY to AUG Mon-Fri.
For time prebook on website.
Fee: free.
rib62: Adult DKK 495.
Classification: Speleologysea cave
Light: bring torch
Dimension: L=650 m, V=348,000 m³.
Guided tours: D=90 min, MinAge=8. English
Photography: allowed
Accessibility: no
Bibliography: Dave Bunnell (2004): Riko Riko Cave, New Zealand—World’s Largest Sea Cave?, NSS News, May 2004, 62 (5): 145–147. online
Address: rib62, Bakkavegur 2, 176 Velbastaður, Tel: +298-566262. E-mail:
As far as we know this information was accurate when it was published (see years in brackets), but may have changed since then.
Please check rates and details directly with the companies in question if you need more recent info.


2018 Magni Laksafoss, Thormann Kruse, and Torkil Zachariassen measure the volume of the cave to be 348,000 m³.


Klæmintsgjógv is a sea cave of enormous size which is visited on boat tours. There are two huge cracks in the rock which run east west. Both were widened by the erosion of the sea and form straight sea caves, one is called Klæmintsgjógv, the second Húsagjógv Both are crossed in a right angle by a third crack which was also widened to a cave named Trongugjógv and runs north-south. All three caves have their own name, they were named before anyone dared to enter them, later the internal connection was discovered. We guess you already mentioned: gjógv is the Faroese word for cave.

Klæmintsgjógv is touted as the world's largest sea cave, sometimes even as the world's largest cave. Even considering the second is a Freudian slip by a marketing genius or a typo, the first statement is obviously nonsense. In 2018 Faroese explorers Magni Laksafoss, Thormann Kruse, and Torkil Zachariassen measured the volume of the cave to be 348,000 m³. Unfortunately we have no idea how good this result is, as far as we know it was published by newspapers, but never in a speleological publication. The number of exaggerated guesstimates is overwhelming, as a result cavers have a simple method to determine the ranking, which follows scientific 101. There is one guy who collects the data, people who want to be listed have to prove their result, and then it is added. For many years Bob Gulden has published the WORLDS LONGEST SEA CAVES list. Unfortunately there is no list by volume, the reason is simple: volume is generally determined by laser scanning, and requires special laser scanners which do not require solid ground. The first cave which was measured was Riko Riko Cave in New Zealand, in 2004, and the volume was 220,000 m³. At this point there was a list, and it had a single entry. That's the obvious reason, why Bob Gulden has not created a list so far: a list with a single entry makes no sense. And that's the reason why Dave Bunnell's article has a question mark. If we believe that the survey of the cave has the necessary accuracy and the volume of 348,000 m³ is correct, this makes a list of two caves. In other words, considering ranking the list only tells us only one thing: this cave is bigger than a cave in New Zealand. And 20 years later Bob Gulden still has not started a list by volume.

An annual "grotto concert" takes place inside the cave during summer. The natural sounds and acoustics of the cave are an integral part of the music. The concerts are organized by Kristian Blak as a part of the Summartónar festival. Spectators enter the cave in small boats. The musicians leave the boats at the end of the cave and play on the huge blocks which form the rugged cave floor.

The sea caves of Hestur are visited by boat, those boat trips typically start at Gamlarætt harbour on the Streymoy island, which can be reached by car or taxi. The boat goes around the island and shows all caves and other stuff, many birds, probably some dolphins and whales too. The direction, if they enter the caves, and if they even go, depends mainly on the weather. Obviously good weather makes it possible to enter all the caves, not so good weather makes the trip more thrilling and is probably better for taking pictures, but with bad weather the tours do not start at all. Other sights on the tour are Loftið, a 365 m high vertical or overhanging cliff, Álvagjógv, another sea cave, the Ólvagjógv gorge and the Trøllhøvdi sea cave. The Mortansholu is a rather small cave in the vertical wall of a huge crack. The entrance is a bit above sea level and reaching it requires a jump up from the boat. We are not sure how this cave formed, but it is obviously not a sea cave, probably it is a blister cave which was widened by erosion.