The Silfra fissure, a crack between the North American and the Eurasian continents located in Iceland’s Thingvellir National Park, is the only place in the world where it’s possible to dive between two tectonic plates. This is both where they meet and where they drift apart (2cm per year), meaning in some parts the plates are so close together you can actually touch both continents at the same time.
This is one of the world’s top diving and snorkeling destinations and you’ll understand why after watching this video. Now you have another reason to visit Iceland. Not that you needed one.