The Great Blue Hole is the most popular dive destination in Belize. This massive hole under the water is near the Lighthouse Reef and creates a perfect circle of deep blue water. The water is 407 feet deep. It's breathtaking.
The Blue Lagoon geothermal spa is one of the most visited attractions in Iceland. The steamy waters are part of a lava formation. The spa is located in a lava field in Grindavík on the Reykjanes Peninsula, southwestern Iceland.