The 2010 eruption that grounded roughly 100,000 flights across Europe came from a volcano only 1,651 metres high. Eyjafjallajökull is small by Icelandic standards. Its ice cap covers about 80 square kilometres, a white lid over a caldera some 2.5 kilometres wide. Beneath it lies basalt and hyaloclastite laid down over roughly 800,000 years. The name is literal: island, mountain, glacier. Operators running Eyjafjallajökull Snowmobiling Tour tours work the firn fields above that crater rim, on snow that rarely leaves. Farmers at Þorvaldseyri, on the southern flank, recorded the eruption of 1821 to 1823 in parish letters. Ash fell grey over the hayfields then, as it did in 2010. The Gígjökull outlet glacier once spilled north into a small lagoon. Meltwater from the 2010 event emptied that basin in a single afternoon and packed it with sediment. Road 249, the approach still used today, was closed by flooding that April and cleared again within weeks. The volcano has erupted three times in recorded history, in 920, 1612 and 1821. Each event drew attention to its larger neighbour, Katla, beneath Mýrdalsjökull. What survives is a working landscape rather than a monument. Sheep graze the lower slopes near Seljalandsfoss. Tracked vehicles and modified superjeeps stage at Brú on Road 249, in 861 Hvolsvöllur, and glacier snowmobile rides on Eyjafjallajökull begin at the snowline rather than the summit. Vélsleðaferð á Eyjafjallajökli, the Icelandic phrase for the activity, predates the visitor boom by decades. Mountain rescue units trained on these slopes long before the first commercial machines arrived, and their route knowledge still shapes where operators run. Weather stations at the margin log wind gusts that regularly exceed anything recorded on the coast below. The ice is the collection here. Crevasse fields open along the eastern margin each summer as the firn line retreats upslope. Nunataks of black scoria break the white surface where the 2010 tephra settled thickest. Southward, the Westman Islands sit offshore; northward, the interior highlands begin. The summit ridge holds two smaller craters that predate the modern caldera. Below the snow, geothermal heat keeps the base of the ice mobile, which is why the surface shifts season to season and why guided routes are re-marked rather than fixed. The mountain has no gate, no ticket office and no fixed path across the glacier. Eyjafjallajökull Snowmobiling Tour tickets are priced independently by the operators who hold permits for the ice cap; the site itself carries an entrance fee of 0 ISK. That distinction — free ground, paid machine time — has held since the first commercial ascents.