Öskjuvatn

Öskjuvatn is a deep crater lake lying in the floor of the Askja caldera in Iceland’s central highlands; it is among the country’s deepest lakes at roughly 220 metres depth and occupies a volcanic caldera. The lake and surrounding caldera are major features of the Askja volcanic system.

The lake fills the central caldera and is ringed by steep cliffs and basaltic slopes; nearby is the smaller geothermal crater lake Víti, located on the caldera rim. The landscape is volcanic and sparsely vegetated, with dramatic contrasts between dark lava and pale ash deposits.

Öskjuvatn formed as part of the Askja eruptions in the late 19th century during major explosive activity that reshaped the caldera. Since then the lake and caldera have been the subject of geological study and occasional volcanic unrest.

The lake is in Iceland’s central highlands and is reached via highland tracks (F-roads) from the northeast and east; access is seasonal and requires suitable vehicles or guided trips from regional centres such as Mývatn or Egilsstaðir.

• Depth and formation: One of Iceland's deepest lakes at roughly 220 metres, formed within the Askja caldera during a major 19th-century eruption.
• Access and seasonality: Remote highland access - roads are rough F-roads and typically open only in summer; travel requires a high-clearance 4x4 or guided tour.

What to See #

• Víti crater lake: Víti is a smaller, geothermal crater lake located on the Askja caldera rim, notable for yellowish tufa and occasionally used for supervised bathing when conditions allow.
• Caldera rim viewpoints: The rim and caldera edges provide elevated viewpoints that show the full length of Öskjuvatn and the steep walls of the volcanic caldera.