The Blue Lagoon Geothermal Spa, Grindavík, Reykjanes Peninsula, Iceland

The lagoon is fed by the water output of the nearby geothermal power plant Svartsengi and is renewed every 2 days. Superheated water is vented from the ground near a lava flow and used to run turbines that generate electricity. After going through the turbines, the steam and hot water passes through a heat exchanger to provide heat for a municipal hot water heating system. Then the water is fed into the lagoon for recreational and medicinal users to bathe in.
Iceland has a strict code of hygiene and guests are required to shower without clothing in the communal shower area before and after bathing.
It is claimed that in June 2007 the Blue Lagoon appeared green, bewildering both residents and tourists of Iceland.
The Blue Lagoon was used as the pit stop for the first leg of The Amazing Race 6. The Blue Lagoon was used for the thermal spa scenes in the filming of Hostel: Part II. It was also shown in the Incubus documentary Look Alive, when the band visited Iceland. It was also shown in fifth cycle of Britain's Next Top Model which used as photoshoot location.