Fifty kilometres north of Iceland’s Þingvellir National Park, a drop of water melts from the glacier Lángjökull, liberated from the 1,000-year-old frozen mass. The drop falls into porous, volcanic rock where it spends 30 to 100 years being filtered through the ground until it emerges into the cracks and fissures that skirt Þingvellir lake. By the time it reaches these fissures and this lake, it is some of the most pristine water in the world.
The most notable fissure to be found along Þingvellir lake is the Silfra fissure, a rift in the earth’s crust between the North American and Eurasian tectonic plates. When you step into the near-freezing water of the Silfra fissure as a diver or snorkeler, you are literally stepping between two continents. This is a dark, cold and spectacular place.