Askja (ˈascja) is a stratovolcano

Stratovolcano

A stratovolcano, also known as a composite volcano, is a tall, conical volcano built up by many layers of hardened lava, tephra, pumice, and volcanic ash. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile and periodic, explosive eruptions...

 situated in a remote part of the central highlands

Highlands of Iceland

The Highlands of Iceland cover most of the interior of Iceland. They are situated above 400–500 metres and are mostly an uninhabitable volcanic desert, because the water precipitating as rain or snow infiltrates so quickly into the ground that it is unavailable for plant growth, which results...

 of Iceland

Iceland

Iceland , described as the Republic of Iceland, is a Nordic and European island country in the North Atlantic Ocean, on the Mid-Atlantic Ridge. Iceland also refers to the main island of the country, which contains almost all the population and almost all the land area. The country has a population...

. The name Askja refers to a complex of nested caldera

Caldera

A caldera is a cauldron-like volcanic feature usually formed by the collapse of land following a volcanic eruption, such as the one at Yellowstone National Park in the US. They are sometimes confused with volcanic craters...

s within the surrounding Dyngjufjöll mountains, which rise to 1510 m (4,954 ft), askja meaning box or caldera in Icelandic
The region is only accessible for a few months of the year. Being situated in the rain-shadow to the NE of the Vatnajökull icecap, the area receives only about 450 mm of rainfall annually.