Every winter, as temperatures drop, natural ice caves form inside the glaciers around Vatnajökull. The caves that develop in the outlet glaciers accessible from Höfn are among the most impressive in Iceland — vaulted chambers of compressed glacial ice in shades of blue from powder to deep cobalt, sculpted by meltwater into shapes that change from one season to the next. The silence inside, broken only by the creak of the ice, is unlike anything above ground.
The season runs roughly November through March, when the ice is cold enough to be safely entered. Outside those months, the caves become unstable and the guides will not take you in — and you should not go on your own. Tours depart from Höfn and typically run three to five hours including the drive to the cave entrance. Numbers are limited by the cave capacity, so book well ahead if visiting in December or January when demand peaks. The caves are not the same ones every year — the glacier's movement and melt shape new chambers each season, and the guides discover them in October.