<P> The Blue Lagoon (Icelandic: Bláa lónið) is a geothermal spa in southwestern Iceland . The spa is located in a lava field near Grindavík on the Reykjanes Peninsula, in a location favourable for geothermal power, and is supplied by water used in the nearby Svartsengi geothermal power station . The Blue Lagoon is approximately 20 km (12 mi) from Keflavík International Airport, and is one of the most visited attractions in Iceland . </P> <P> The warm waters are rich in minerals like silica and sulfur and bathing in the Blue Lagoon is reputed to help some people suffering from skin diseases such as psoriasis . The water temperature in the bathing and swimming area of the lagoon averages 37--39 ° C (99--102 ° F). The Blue Lagoon also operates a research and development facility to help find cures for other skin ailments using the mineral - rich water . </P> <P> The lagoon is a man - made lagoon which is fed by the water output of the nearby geothermal power plant Svartsengi and is renewed every two days . It is the largest in the world . 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 water heating system . Then the water is fed into the lagoon for recreational and medicinal users to bathe in . </P>

What temperature is the blue lagoon in iceland
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