The Blue Lagoon is a world-famous geothermal spa located on the Reykjanes Peninsula, about 45 minutes from Reykjavik. The spa features a large outdoor pool filled with naturally heated geothermal water, which is rich in minerals and believed to have therapeutic properties. Visitors can relax in the warm waters, enjoy a massage, or even apply a silica mud mask for a unique spa experience. The Blue Lagoon is a popular destination year-round, so it's recommended to book tickets in advance.