In between soaking in geothermal spas, visiting thundering waterfalls, and eating the famous (but pretty weird) Icelandic hot dogs – you’re going to want to fit in a visit to Thingvellir National Park. Sure, there are historic sites and some cool hikes – but the real reason to trek out here is for the diving. There’s no coral, but this might be even better because it’s your only chance to safely dive between two continental plates. The Silfra Fissure is a narrow gap between the North American and Eurasian plates filled with perfectly crystal clear water and eerily colorful algae. There’s nothing else quite like it in the world, so get out of Reykjavik for the day and get to diving!