Dominating the lava fields on the eastern edge of Mývatn is the classic tephra ring Hverfell (also called Hverfjall). This near-symmetrical crater appeared 2700 years ago in a cataclysmic eruption of the existing Lúdentarhíð complex. Rising 463m from the ground and stretching 1040m across, it is a massive and awe-inspiring landmark in Mývatn.
The crater is composed of loose gravel, but an easy track leads from the northwestern end to the summit and offers stunning views of the crater itself and the surrounding landscape. A path runs along the western rim of the crater to a lookout at the southern end before descending steeply towards Dimmuborgir.
Access to the walking track at the ring's northwestern end is via a signed gravel road – it's about 3km from the main road to the car park.
