The uninhabited, mountainous area to the east of the big icecap Vatnajokull is called Lonsoraefi. Its southern boundaries are the valley Skyndidalur, the low mountain Geldingafell in the north and the small glacier Hofsjokull and the uppermost part of the valley Vididalur in the east. The whole area is carved with gullies and gorges and coloured by many rhyolitic intrusions. It is very rich in half precious stones, such as opals, jaspers, rock crystals, zeolites, chalcedony and mordenite.

A jeep track, which ends on the so-called Illikambur ridge, connects the area with the main road and during summer there are daily tours from the town Hofn in the Southeast. The Lonsoræfi is one of the most interesting and beautiful hiking areas of the country and the hikers can choose between tourist huts or pitching their tents on the way.

After the establishment of Europe's largest national park, Vatnajokull, on June 7th, 2008, Lon became one of the centres for the NP wardens.