The dramatic lava cave at Lofthellir is a stunning destination, with magnificent natural ice sculptures dominating the interior. Although it's one of Mývatn’s highlights, the cave is on private property and can only be accessed on a half-day tour with Geo Travel. The tour involves a one-hour 4WD journey and a 25-minute walk across gorgeous lava fields to reach the cave, and then the donning of special equipment (headlamps, studded boots etc) and intensely physical wriggling through tight spaces. Wear warm, waterproof gear.
Winter tours cross snowfields. In summer, you can cycle to the cave with Mývatn Activity – Hike&Bike. While Geo travel runs the tours, they can also be booked via Saga Travel.