Silfra is a fissure in Þingvellir National Park filled with glacial meltwater that has been filtered through porous lava rock for decades, resulting in visibility that can exceed 100 meters.
What the experience is like
You’re fitted with a drysuit, thermal undergarments, and a snorkel mask, then guided along a roughly 350-meter route through the fissure. The water hovers around 2–4°C year-round, but the drysuit keeps you dry and reasonably warm — cold hands and face are the main sensation.
What you’ll see
The draw isn’t marine life — there’s very little — it’s the visibility and the geology: vivid blue water, rock walls from two continental plates, and bright green algae in certain sections (nicknamed “troll hair”).
Booking and requirements
Tours run year-round and must be booked through licensed operators — independent snorkeling isn’t permitted. Most operators have minimum age and basic health requirements due to the cold water; full scuba diving is also available for certified divers.
Is it worth it?
For most visitors, yes — it’s a genuinely unusual experience and one of the few ways to be physically in the rift between two tectonic plates. Combine it with a Golden Circle day, since Þingvellir is one of the three main stops.
About Erika Sand
Erika has spent the last decade driving, hiking, and hot-spring-hopping across Iceland in every season. She writes NRF.is’s itineraries, guides, and trip reports to help travelers see the country safely, affordably, and without the tourist-trap detours.