Key takeaways
- Drift between continental plates in Iceland's clearest freshwater. Your PADI guide provides all thermal gear and captures underwater moments as you explore the rift.
- This UNESCO site straddles two tectonic plates pulling apart. The visible rift valley demonstrates Earth's geological forces and holds profound cultural meaning for Icelanders.
- After snorkeling, explore Oxararfoss waterfall and Almannagja gorge on the same park ticket. Allow 1 to 2 hours for these walks depending on your pace.
- The Drowning Pool and Peningagja coin fissure sit within walking distance. Screen fans recognise the rift walls from major film productions shot here.
- Plan 5 hours 30 minutes total. Includes snorkel time, gear, hot cocoa recovery, guide expertise, park entry and return transport from Reykjavik.
Oxararfoss: The Waterfall Within Reach
Your snorkeling adventure at the Silfra Fissure takes place within Thingvellir National Park, where a short walk leads to Oxararfoss, a modest but striking waterfall fed by the Öxará river. The cascade drops into a canyon carved by the same geological forces that created the fissure where you'll snorkel. Most visitors combine both in a single visit, using the park admission fee that covers entry to all walking trails and natural features. The waterfall is accessible via a well-marked path from the main visitor area, adding no more than 20 minutes of walking to your day.
The water you see falling at Oxararfoss originates upstream and eventually flows into the Silfra Fissure lake, making it part of the same hydrological system you'll experience underwater. The gorge around the waterfall offers excellent photography and a chance to see the rift valley's scale from above before descending into it during your snorkel.
Almannagja: Walking the Rift Valley Walls
The Almannagja gorge forms one side of the visible rift between the North American and Eurasian tectonic plates. Walking along its edge provides context for what you'll experience in the water: you can stand on continental crust and see the opposing plate's cliff face across from you, separated by the spreading zone. The trail runs alongside these dramatic rock walls, which rise steeply and expose layers of lava flows accumulated over thousands of years. Depending on your fitness and time, you can walk sections ranging from 15 minutes to over an hour.
The gorge walls reveal Iceland's volcanic history in cross-section. Dark basalt layers alternate with lighter weathered rock, and in summer, vegetation clings to crevices where moisture collects. This walk gives you the geological story that the snorkel experience illustrates: you're literally walking between two continents as they drift apart at a rate of about 2 centimeters per year.
Peningagja: The Coin Fissure and Its Tradition
Within the park stands Peningagja, a narrow fissure known as the coin fissure because of a long-standing tradition of tossing coins into its depths. Visitors have dropped currency here for decades, and the coins have accumulated at the bottom in remarkable quantities. The fissure is only a few meters wide but descends far deeper than it appears from the rim, creating an irresistible target for those making wishes. Unlike the Silfra Fissure where you'll snorkel, Peningagja is not accessible for water entry and serves as a viewpoint and curiosity rather than an activity site.
The coins themselves tell a story of hope and superstition. Icelandic króna, euros, and coins from dozens of other countries rest in the fissure's bottom. Local guides often explain that the tradition persists despite park rules discouraging it, and the accumulated coins have occasionally been donated to charity. It's a brief but memorable stop on any walk through Thingvellir's landscape of natural wonders.
Thingvallavatn: The Glacial Lake's Hidden Depths
The Silfra Fissure opens into Thingvallavatn, a vast glacial lake that covers approximately 84 square kilometers and reaches depths of 114 meters in places. This lake is Iceland's second-largest body of water and serves as the natural basin into which the rift valley's water drains. When you snorkel the fissure, you're entering the shallow end of this enormous lake, where the water clarity is exceptional due to the lack of sediment in glacial meltwater. The lake's size is difficult to grasp from the shore, but from underwater you can sense the vastness above as you drift.
The temperature of Thingvallavatn remains cold year-round, which is why the thermal undersuit provided with your snorkeling gear is essential. The glacial source keeps the water refreshingly clear and contributes to the underwater visibility that makes the Silfra Fissure experience so remarkable. The lake's ecosystem is adapted to these conditions, and Arctic char thrive in its depths.
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Thingvallavatn lake stretches across 84 square kilometres within the rift valley.
The Drowning Pool: A Grim Chapter in Iceland's History
Thingvellir holds a haunting historical significance as the site where women accused of witchcraft and infanticide were executed by drowning. A specific location within the park, sometimes called the Drowning Pool, marks where these judicial killings took place during Iceland's darker centuries. The executions followed trials at Thingvellir's historic assembly grounds, and records document dozens of women meeting this fate between the 1600s and 1700s. Today, a memorial acknowledges this tragic history, and visitors often pause to reflect on these losses while walking the park's trails.
Understanding this history adds weight to a visit to Thingvellir. The same landscape that showcases geological marvels and natural beauty was also witness to injustice and suffering. Many tour operators and guides mention this aspect when explaining the park's cultural significance, placing the natural wonders within a complete historical context that Icelandic people do not shy away from acknowledging.
UNESCO World Heritage Status and Geological Significance
Thingvellir earned UNESCO World Heritage designation in 2004 for its exceptional geological and cultural importance. Geologically, it represents one of the few places on Earth where a mid-ocean ridge is visible above sea level, allowing direct observation of plate tectonics in action. The visible rift between the Eurasian and North American plates makes it an outdoor classroom for understanding Earth's structure. When you snorkel the Silfra Fissure, you're experiencing this tectonic boundary firsthand in its most direct form, drifting between the two continental plates in water that flows directly from glacial sources.
Culturally, Thingvellir holds equal significance as the historical seat of Iceland's parliament, established in 930 and called the Althing. The assembly met in the open air within the rift valley's dramatic setting, making it one of the world's oldest parliamentary sites. This combination of geological rarity and cultural heritage creates a destination where natural processes and human history intertwine, both visible and comprehensible to visitors walking the same ground where these forces converge.
The Rift Valley in Film and Television
The dramatic rift walls and landscape of Thingvellir have attracted filmmakers and television producers seeking visually striking natural locations. Several well-known productions have shot scenes among the Almannagja gorge walls and rift formations, using the otherworldly appearance of the canyon to create alien or fantasy environments. The sheer rock faces, the stark vegetation, and the sense of standing between two worlds make the location naturally cinematic. While specific scenes change as new productions film here, the distinctive formations remain recognizable to fans of Icelandic filming locations.
Visitors often enjoy identifying filming locations during their walks, adding an entertainment layer to the geological and historical experiences. Guides familiar with production histories can point out notable spots, and the dramatic lighting during different times of day transforms the rift's appearance. Whether you're a film enthusiast or simply appreciating the landscape's raw beauty, the visual drama of the rift valley speaks for itself.
