Lónsöræfi, (“The Lagoon wilderness”) a broad unbuilt area east of Vatnajökull. In recent years it has become increasingly popular to walk in
this area, huts have been put up and footbridges built on the most difficult
rivers. Before the “mini-ice age” of 1600-1900 people travelling between
different parts of Iceland often crossed Lónsöræfi, for instance from
Þingeyjarsy´sla county in the north to Hornafjörður in the southeast. This
may explain why both the rivers Jökulsá í Lóni and Víðdalsá have fords
called Norðlingavað (“Northerners’ ford”).
Lónsöræfi is rugged and dramatic countryside, very colourful. The central volcano piled its lava on top of that from the Álftafjarðar volcano by the Þvottá river.
The mountains have numerous needles and pinnacles and are scored by
canyons, so it is vital to follow designated walking routes carefully. To
the north of Lónsöræfi is Hraun, a rocky moorland area of frequent fogs
and snows, reaching north to Fljótsdalur. Apart from the glaciers, no
place in Iceland has more precipitation. When it rains, rivers in the area can become unpassable torrents without warning.
source Iceland Road Atlas