Iceland — Reykjavik
Ascend through Iceland's dramatic Hvalfjörður on the Glymur Waterfall trail. This moderate 7.0 km loop offers stunning panoramas of deep canyons and a powerful cascade, a former national record holder. Expect river crossings and a 400m ascent through pristine wilderness, a rewarding day out from Reykjavik.
Distance: 7.0 km
Elevation Gain: 400 m
Difficulty: Moderate
Duration: 3-4 hours
The Glymur Waterfall hike is one of Iceland's most rewarding day excursions, offering a dramatic blend of deep canyons, river crossings, and the sheer majesty of what was long considered the country's highest waterfall. Located in the profound silence of Hvalfjörður (the Whale Fjord), just a short drive from the capital city of Reykjavik, this 7.0-kilometre loop trail ascends 400 metres through a landscape that feels ancient and untouched. Unlike the easily accessible waterfalls along the Ring Road, Glymur requires effort, balance, and a spirit of adventure to witness. The trail leads hikers through a natural cave, across a rushing glacial river via a narrow log bridge, and along the precipitous edges of the Glymsgil canyon, where the Botnsá river plunges 198 metres into a moss-covered abyss. This is not merely a walk to a viewpoint; it is a multi-sensory journey through the geological heart of West Iceland, where the roar of falling water competes with the cries of northern fulmars nesting in the cliff faces.
For decades, Glymur held the undisputed title of Iceland’s tallest waterfall. While the discovery of Morsárfoss in the Vatnajökull glacier region in 2007 technically relegated Glymur to second place, it remains the most spectacular and accessible of Iceland’s "giant" falls. The waterfall is fed by the river Botnsá, which flows out of the crystal-clear Hvalvatn lake, situated high on the plateau above. The water drops 198 metres down a narrow, twisting canyon that is so deep and sheer that parts of the waterfall are often obscured from view until you reach the highest vantage points. The surrounding canyon, Glymsgil, is a masterpiece of volcanic erosion, draped in vibrant green mosses and inhabited by thousands of seabirds that find sanctuary in the vertical basalt walls.
The hike itself is a classic Icelandic loop that provides two distinct perspectives of the canyon. Most hikers choose to ascend via the southern side of the canyon, which offers the most direct and dramatic views of the falls, and descend via the northern side. This route involves a famous river crossing at the base of the canyon. During the summer months, a sturdy log with a handrail is placed across the Botnsá river to facilitate the crossing. Without this log, the hike becomes significantly more technical and dangerous. The ascent is steep in places, requiring the use of fixed cables to navigate slippery volcanic rock and loose scree, but the reward is a series of viewpoints that offer a humbling sense of scale. From the top, the view extends back down the length of Hvalfjörður, a fjord that remains largely bypassed by the modern tunnel, preserving its quiet, majestic character.
What sets Glymur apart from other Icelandic landmarks is the lack of commercialisation. There are no visitor centres, gift shops, or paved pathways here. The trail is marked by simple wooden stakes and yellow paint on rocks, maintaining a raw connection to the wilderness. It is a hike that demands respect for the elements—Icelandic weather can shift from brilliant sunshine to horizontal rain in minutes—but for those prepared for the challenge, it offers one of the most profound natural experiences in the North Atlantic.
The area surrounding Glymur and Hvalfjörður is steeped in both geological history and local folklore. Hvalfjörður, or "Whale Fjord," takes its name from the large number of whales that were historically found in its deep waters. During World War II, the fjord served as a critical strategic naval base for the British and American militaries. Because of its depth and the protection offered by the surrounding mountains, it was used as a staging ground for Atlantic convoys. Remnants of this military history, including old piers and foundations, can still be seen along the coastline of the fjord today.
However, the most enduring story associated with Glymur is the legend of Rauðhöfði (Redhead). According to Icelandic folklore, a man broke a promise to a woman of the hidden people (Huldufólk). In revenge, she cursed him, transforming him into a monstrous, red-headed whale that terrorised the waters of Hvalfjörður, sinking ships and drowning locals. An old, blind priest, whose two sons had been killed by the whale, eventually lured the beast into the fjord using his spiritual powers. He guided the whale up the Botnsá river, which was a feat of immense difficulty. As the whale struggled up the narrow canyon and leaped over the waterfall, the earth shook so violently that the sound—the "glymur" (clash or resonance)—gave the waterfall its name. The whale eventually reached Lake Hvalvatn, where it died of exhaustion. To this day, locals claim that whale bones have been found near the lake, and the legend serves as a reminder of the powerful, often vengeful, forces of nature in Icelandic culture.
Geologically, the canyon was carved over millennia by the Botnsá river, which cut through layers of basaltic lava flows. The sheer walls of the canyon provide a vertical timeline of Iceland's volcanic activity, with distinct layers of rock representing different eruptive periods. The presence of the waterfall is a result of the post-glacial rebound and the specific topography of the Hvalvatn plateau, which forces the river to make a dramatic descent to reach the sea level of the fjord.
Want more background? Read extended notes on history and cultural context → Learn more
The Glymur hike is strictly a seasonal experience for the majority of hikers. The most critical factor is the presence of the log bridge over the Botnsá river. This log is typically installed by the local hiking club or authorities in late May or early June and removed in late September or early October to prevent it from being swept away by winter floods and ice. Without the log, the river crossing is extremely dangerous, involving wading through fast-moving, freezing glacial water over slippery boulders.
Summer (June to August): This is the peak season for Glymur. The days are long, often with 24 hours of daylight in June, allowing for late-evening hikes in the "midnight sun." The moss in the canyon is at its most vibrant green, and the birdlife is highly active. However, this is also the time when the trail is most crowded. While never as busy as the Golden Circle, the parking lot can fill up by midday. Temperatures typically range from 8°C to 15°C, but the wind chill in the canyon can make it feel much colder.
Shoulder Season (May and September): These months offer a quieter experience, but weather becomes more unpredictable. In May, there may still be snow patches on the upper plateau, and the log bridge might not yet be in place. In September, the autumn colours begin to turn the surrounding heathland into shades of gold and burnt orange. The log is usually removed by the end of September, so hikers visiting later must be prepared to either wade the river or treat the hike as an out-and-back trail on one side of the canyon.
Winter (October to April): Hiking Glymur in winter is an advanced undertaking and is generally not recommended for recreational hikers. The trail becomes treacherous with ice, especially on the steep sections and cliff edges. The river crossing is impossible without the bridge, and the daylight hours are extremely limited. Strong winds in Hvalfjörður can reach hurricane force, making the exposed ridges of the hike life-threatening. If attempting the area in winter, hikers should stay on the lower paths and avoid the canyon edges entirely.
Phase 1: The Trailhead to the Cave (Þvottahellir)
Phase 2: The River Crossing and Initial Ascent
Phase 3: The Canyon Rim and Main Viewpoints
Phase 4: The Upper River Crossing and Descent
Important Notes:
Preparation for Glymur begins with transport. While many of Iceland's attractions are accessible by public bus or tour groups, Glymur is best reached via a rental car. From Reykjavik, you have two choices: the fast route through the Hvalfjarðargöng tunnel (Route 1), or the scenic route around the fjord (Route 47). To reach the trailhead, you must take Route 47. If coming from the south, turn onto Route 47 before the tunnel entrance. The drive takes approximately 60 to 90 minutes depending on weather and road conditions. The final stretch to the parking lot is a gravel road; while a 4x4 is not strictly required in summer, high clearance is beneficial.
Physical fitness is a consideration. While the hike is only 7 kilometres, the 400-metre elevation gain is concentrated in steep, rocky sections. Hikers should be comfortable with heights (vertigo can be an issue on the canyon rim) and have the balance required for river crossings and cable-assisted climbing. There are no facilities at the trailhead—no toilets, no water taps, and no rubbish bins. Ensure you use facilities in Reykjavik or at the petrol stations along Route 1 before turning into the fjord.
This is a day hike requiring no overnight accommodation on the trail itself. Camping is strictly prohibited in the immediate vicinity of the trailhead and the canyon to protect the fragile moss and ecosystem. However, there are several options for staying nearby if you wish to explore Hvalfjörður more deeply.
Nearby Options:
Currently, no permits are required to hike to Glymur Waterfall. Access to the trail and the surrounding land is free for the public, reflecting Iceland's traditional "right to roam" (Almannaréttur), provided that visitors respect the land and follow established paths. There is no entrance fee for the parking area, though this is subject to change as Iceland continues to develop its tourism infrastructure.
Key Considerations:
Detailed route notes, maps, logistics & tips for the Glymur Waterfall Hike (PDF).
Precisely traced GPX for the Glymur Waterfall Hike, ready for your GPS or favourite mapping app.
Hvalfjörður is often overlooked by tourists rushing to the North or West, but it contains several hidden gems worth exploring before or after your hike:
Pre-Departure Checks:
Specific Hazards:
The Log Bridge: The crossing is narrow. If you have a poor sense of balance, use the cable and move slowly. If the log is wet, it can be extremely slippery. Only one person should be on the log at a time to prevent excess vibration.
Cliff Edges: The trail along the canyon rim is not fenced. The drop-offs are sheer and nearly 200 metres deep. Stay well back from the edge, especially in gusty winds. The volcanic soil can be unstable, particularly after heavy rain.
The Upper River Crossing: If you choose to do the loop, you must wade the river above the falls. Never attempt this if the water is above knee height or if the current feels too strong. Loosen your backpack straps before crossing so you can jettison the pack if you fall. Use trekking poles for three points of contact at all times.
Slippery Rocks and Mud: The ascent involves scrambling over basalt rocks that become like ice when wet. Use the provided steel cables. On the descent, be wary of "loose ball bearings"—small volcanic pebbles on hard surfaces that can cause slips.
Hypothermia: Even in summer, if you get wet and the wind picks up, hypothermia is a real risk. Always carry your waterproof layers and a warm hat.
Þvottahellir (The Washing Cave): This cave near the start of the hike was historically used by locals for shelter and, as the name suggests, potentially for washing or drying items during long journeys. It provides a unique "tunnel" experience as the trail passes directly through it.
Hvalfell Mountain: For very fit hikers, the trail can be extended to summit Hvalfell (852 m), the prominent flat-topped mountain to the east of the waterfall. This requires significant extra time and navigation skills but offers a bird's-eye view of both Glymur and the massive Hvalvatn lake.
Hvalvatn Lake: If you continue past the upper river crossing for a few kilometres, you will reach the shores of Hvalvatn. It is one of Iceland's deepest lakes (160 m) and sits in a stark, beautiful volcanic bowl. The silence here is profound, as few hikers venture past the waterfall.
Botnssúlur Peaks: The "Peaks of the Bottom" are a cluster of rhyolite mountains visible to the south. They are part of a much longer hiking route (the Leggjabrjótur trail) that connects Hvalfjörður to Þingvellir National Park. While not a side trip for a single day, they provide a stunning backdrop to the Glymur hike.
Iceland's nature is rugged but incredibly fragile. The sub-arctic ecosystem grows slowly, and the damage caused by a single footstep off the trail can take decades to heal. As Glymur grows in popularity, the impact on the trail is becoming visible.
Your responsibility as a hiker:
