The unique qualities of Vatnajökull National Park are primarily its great variety of landscape features, created by the combined forces of rivers, glacial ice, and volcanic and geothermal activity.

Nowhere in Iceland, with the exception of Mýrdalsjökull glacier, does more precipitation fall or more water drain to the sea than on the south side of Vatnajökull.

The mighty Dettifoss waterfall still thunders into the upper end of this canyon, while the scenic formations at Hljóðaklettar [ˈl̥jouːðaˌkʰlɛhtar̥] and the horseshoe-curved cliffs of Ásbyrgi are found farther north.

The south side of Vatnajökull is characterised by many high, majestic mountain ridges, with outlet glaciers descending between them onto the lowlands.

Sheltered by the high ice, the vegetated oasis of Skaftafell overlooks the black sands deposited to its west by the river Skeiðará.

These sands are mostly composed of ash which stems from the frequent eruptions at Grímsvötn and is brought to the coast by jökulhlaups, or glacial floods.

Substantial volcanic activity also characterises the landscape west of Vatnajökull, where two of the world's greatest fissure and lava eruptions of historical times occurred, at Eldgjá in 934 and Lakagígar 1783–1784.

The weather can vary considerably in an area as extensive as that covered by the National Park with its wide range of elevations.

Northerly winds bring clouds, with cool and possibly wet weather in the north of the country, while the south is brighter and milder.

The reverse is true of easterly winds, which bring coolness and precipitation in the east and dry, better weather in the west of Iceland.

The Northern Territory consists of north-western Vatnajökull, Askja caldera and its surroundings, Jökulsárgljúfur canyon and some of Jökulsá á Fjöllum riverbed.

The Southern Territory extends throughout the south-eastern part of Vatnajökull, or from Lómagnúpur mountain in the west to Lón [ˈlouːn] and Lónsöræfi in the east.

The Western Territory extends over the south-western part of Vatnajökull and a large area outside the glacier, including Lakagígar craters and Langisjór.