Blue Lagoon: Iceland's geothermal spa

The Blue Lagoon geothermal spa is one of the largest attractions in Iceland. The steamy waters are part of a lava formation, and a large swimming pool is heated with the run-off water from a nearby geothermal power plant. Superheated water is vented from the ground near a lava flow and used to run turbines that generate electricity. After passing through the turbines the steam and hot water passes through a heat exchanger to provide heat for a municipal hot water heating system. The water is then fed into the lagoon for users to bathe in. The warm waters are rich in minerals such as silica and sulfur. Bathing in the Blue Lagoon for therapeutic purposes 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 40°C (104°F). The spa is located in a lava field in Grindavík on the Reykjanes Peninsula, southwestern Iceland. It’s situated about 24 miles (39 kilometers) from the capital city of Reykjavík. (Photos: Diamanx and Sandro Mancuso)