What is Askja and where is it?

Lake Askja and the crater Víti, both inside the caldera in the center highland of Iceland.

Askja is a caldera located in the center highland of Iceland, in the mountains Dyngjufjöll. Inside the caldera is a deep lake, and a crater with geothermal water. It is sometimes suitable to bathe in it although the path down to the crater is often impassable due to how steep it is.

The trip it self to the Caldera is through the biggest desert of Iceland, called Ódáðahraun, along the glacier river Jökulsá á Fjöllum.