The Kverkfjoll Mountains are at the northern edge of the icecap Vatnajökull. Mts Kverkfjoll contain two vast calderas. The southern caldera is ice-filled, but the rims of the northern caldera are mostly ice-free. The highest part of the rims is the Skarphedin's Peak (1936m).

Mts Kverkfjoll are divided into eastern and western halves by the Kverk, a wide pass between the steep, rocky walls. Glacier Kverkjokull flows through the Kverk pass. Massive glacier snouts extend from the icecap on both sides of Mts Kverkfjoll.

Kverkfjallarani consists of 5-6 parallel hyaloclastite ridges. The glacial river Kreppa flows through an ice-filled valley, discharging the western edge of the Bruarjokull glacier. Another glacial river, Jokulsa á Fjollum, discharges the western part the Dyngjujokull glaciers just west of Mts Kverkfjoll, but further west, other branches disappear into sanded lava fields.

Routes into the area
Ancient sources and legends suggest that people travelled across the icecap in medieval times. The route of those travelling south most likely passed just east of Mts Kverkfjoll until it fell into disuse for centuries on end.  The Mts Kverkfjoll area was first revisited during the latter part of the 19^th century, and in 1910 a German geologist, Trautz, was the first to climb the mountains.

The glacial river Kreppa was bridged in 1970, and a track through Krepputunga, across the Hvannalindir area and through the Kverkhnjukaskard pass to Mts Kverkfjoll was opened. The Tourist Association’s hut, Sigurdarskali, was built at the foot of Mt Virkisfell in the summer of 1971. It is the result of the combined effort of the touring clubs of Fljotsdalsherad, Vopnafiord and Husavik.

Geology
The enormous central volcano, Mts Kverkfjoll are located at and within the northern edge of the icecap Vatnajokull.  They are a part of the active volcanic zone, extending to the Oxarfiord Bay and the Melrakkasletta peninsula in the north and Grimsvotn, Hekla and the Vestman Islands in the south.. Mts Kverkfjoll extend southwest into the Vatnajökull ice cap, and Kverkfjallarani is clearly visible as a gigantic row of peaks extending 30 kilometres to the northeast from Mts Kverkfjoll. They were created mostly by about 40 volcanic eruptions during the last Ice Age. A great number of fissures in the Kverkfjallarani shows, where they occurred. The Lindahraun lava field, less than 2800 years old, is probably the most recent. The hills in the Kverkfjoll range are to a large extent covered in black and reddish scoria from nearby volcanic fissures.  During the past centuries, great floods of River Jokulsa á Fjollum often followed volcanic eruptions in Mts Kverkfjoll and under the Dyngjujokull glacier. A deluge of catastrophic proportions about 2,000 years ago is attributed to eruptions in this area or in Mt. Bardarbunga further west.

Geothermal Activity
One of Iceland's most powerful high temperature areas is located in the western Mts Kverkfjoll. The hot spring area is 3 km long and nearly 1 km wide at 1600-1700 m above sea level. In the southernmost part of the area is the Hveradalur Valley, separated from Hveraskal [Lower Hveradalur Valley] by the Threngsli Pass. In the northern part of the pass is Gamur, one of Iceland's most powerful geysirs. North of the Hveraskal extends a ridge, and above that a surface depression; together, the ridge and depression make up a geothermal tract, which has been named Hveratagl. A hiking trail slants from the Kverkjokull glacier up the Langafonn slope to the ridge and along its edges to The Icelandic Glaciological Society’ hut.

In the southernmost part of the Hveradalur valley is a large lagoon, often filled with ice, often empty. Another water-filled caldera is located just east of The Icelandic Glaciological Society’s hut. The caldera is about 600 metres wide and about 100 metres deep. It was created in 1959 by an explosive, geothermal eruption.

The river discharging the Kverkjokull glacier collects hot, geothermal water, which creates the ice cave above the sub-glacial riverbed.  Large high temperature areas exist under the icecap, and   some scientists claim the sub-glacial length of the river to be close to 30 km.

Vegetation in Mts Kverkfjoll
Mts Kverkfjoll and Kverkfjallarani lie too high above sea level for continuous vegetation. Conspicuous, pale-grey lichens, known as desert cheese (Oeraefaostur; Stereocaulon arcticum), survive in many places in the lava fields of the area. Small patches near the hot springs in ravine Hveragil are rich in vegetation.