The Long Glacier (1355m) is the second largest in Iceland. It has an area of about 950 km² and most of it rises between 1200 and 1300 m above sea level. It rests on a massif of hyaloclastite mountains. They rise highest under its southern and northern parts, but have not yet been researched thoroughly. The Glaciological Society owns a hut at the foot of the nunatak Fjallkirkjan (1228m).
The southwestern part of the icecap is called Geitlandsjokull. It rises to the elevation of 1400 metres. On a fine day the view from up there is excellent.
To the south of Geitlandjokull and separated from the main iceap, is the smaller, 1350 metres high Thorisjokull on top of an irregular table mountain. According to the legend, it was named after the ogre Thorir, who lived in a green valley in the pass between the glaciers.
Many glacier snouts crawl down to the lower lying regions, and each of them has a name.
Still another small glacier is located to the west of the main icecap. Nowadays there is hardly any snow or ice left on top of this mountain, which is called Ok (1198 m), and is very prominent from the so-called Kaldidalur route.
There are two more smaller glaciers around the big one, to the northwest is Eiriksjokull (1575 m), and to the east is Hrutafell.
Very little water runs off from The Long Glacier on the surface. It, however, supplies the largest natural lake of the country and the lakes to the north and geothermal areas in the West and the Geysir area as well.
Organised snowmobile- and snow scooter tours on the icecap ar on offer.
Hiking or cross country skiing on the icecaps depends entirely on the travellers themselves. They decide where to go and are responsible for the preparations and the gear necessary for such endeavours.