Hljóðaklettar
Hljóðaklettar, meaning Echo Rocks, is a cluster of basalt column formations in the Jökulsárgljúfur canyon section of Vatnajökull National Park in North Iceland. Unlike most basalt columns in Iceland, which stand vertically, the columns here run in every direction — horizontal, radial, and curved — creating a labyrinth of caves, arches, and formations with names like Kirkjan (the Church), Kastilinn (the Castle), and Tröllið (the Troll). The curved cave walls reflect sound waves in multiple directions, producing the disorienting echoes that give the site its name.
Basalt Columns Running in Every Direction, Creating Caves That Echo
Most basalt columns in Iceland form when lava cools slowly and contracts along vertical stress lines, producing the upright columns seen at Svartifoss or the Giant's Causeway. At Hljóðaklettar the lava cooled inside the conduit system of an ancient crater row, where the direction of cooling varied depending on the position within the vent. The result is columns that fan outward, twist horizontally, and intersect at unexpected angles, creating the only known occurrence of honeycomb-weathered basalt in Iceland. The formations are the remnants of ancient volcanic plugs, hardened lava cores that were exposed after glacial outburst floods from Vatnajökull stripped away the surrounding softer material over thousands of years. The nearby Rauðhólar (Red Hills) show what the original scoria cones looked like before the same process of erosion.
Two marked hiking trails start from the Vesturdalur parking area. The short blue trail is an easy 1-kilometre walk taking around 30 minutes and passes the main formations including Kirkjan, a cave arch whose curved walls create the most pronounced echo effects on the site. The longer red trail is a 2-hour loop that covers the broader area and connects to the Rauðhólar crater row. Individual formations are named and signposted. The site is also the only place in Iceland where honeycomb weathering can be observed in basalt. Vesturdalur itself is a campsite with facilities and makes a good base for exploring this part of the Diamond Circle.
Hljóðaklettar is located in the Jökulsárgljúfur section of Vatnajökull National Park, accessed via Road 862 on the west side of the canyon, then Road 888 to the Vesturdalur parking area. The site is about 100 kilometres east of Akureyri. It sits between Ásbyrgi canyon to the north and Dettifoss waterfall to the south, making it a natural stop on a Diamond Circle itinerary. The area is open year-round but the gravel access roads can be challenging in winter.
