Sundlaugin (, the swimming pool) is a recording studio located near Álafoss in the town of Mosfellsbær in Iceland known for being the recording and rehearsal location of post-rock band Sigur Rós. The location was originally a swimming pool built in the 1930s which had been abandoned when Sigur Rós purchased it in 1999 and converted it and adjacent buildings into a studio.
The band originally intended to record their third album, titled ( ), in an abandoned NATO tracking base in the northernmost mountain in Iceland, but after inspection decided it was too impractical. Shortly after they found the abandoned pool lot in a rural neighborhood in Mosfellsbær. They bought the lot and transformed it into a studio. In order to fit the massive mixing console into the building, part of the roof was opened up and the console was lowered with a crane.
Much of the band's photography and artwork is taken from the surrounding landscape, such as the art found on the first album recorded in the studio, ( ).
The recording studio has also been used for recording, mixing and mastering (usually assisted by the studio's sound engineer Birgir Jón "Biggi" Birgisson) by a wide group of mainly Icelandic artists and bands, including:
Agent Fresco
The Album Leaf
Alcest
amiina
Amusement Parks on Fire
Bubbi Morthens
Emmanuel De La Paix
Flying Hórses
For a Minor Reflection
Jakobínarína
Julianna Barwick
Langi Seli og Skuggarnir
Mammút
Mugison
Múm
Ólöf Arnalds
Retro Stefson
Seabear
Self Defense Family
Sin Fang
Ske
Slowblow
Steindór Andersen
Stórsveit Nix Noltes
As of 2020, Sundlaugin is owned by Sigur Rós keyboardist Kjartan Sveinsson.