THE BLUE LAGOON, ICELAND, AUGUST 30, 2019: Blue Lagoon, The Famous Geothermal Spa In Southwestern Iceland. Editorial Photo

The Blue Lagoon is a geothermal spa in southwestern Iceland. The spa is located in a lava field near Grindavi­k on the Reykjanes Peninsula, in a location favorable for geothermal power, and is supplied by water used in the nearby Svartsengi geothermal power station. The Blue Lagoon is approximately 20 km from Keflavi­k International Airport, and is one of the most visited attractions in Iceland. The water`s milky blue shade is due to its high silica content. The silica forms soft white mud on the bottom of the lake which bathers rub on themselves. The water is also rich in salts and algae. The lagoon is man-made. The water is a byproduct from the nearby geothermal power plant Svartsengi where 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. The rich mineral content is provided by the underground geological layers and pushed up to the surface by the hot water. Reykjanes Peninsula, southwest Iceland.