Iceland’s Blue Lagoon Georthermal Spa holds geothermal sea water heated to jacuzzi water temps (37-39°C / 98-102°F) beneath the ground. The water, rich in silica and other minerals, is renewed every 40 hours. At first blush I thought that the lagoon itself brought forth the geothermal water, but, but upon reading further, it appears that “the geothermal seawater is brought to the lagoon for people to enjoy bathing in it, and to the R&D centre where its actives are isolated for use in Blue Lagoon skin care.”
No matter. If you’re fond of jacuzzis and mud packs, you’ll love this.