Depth
220 meters
Iceland's deepest lake, filling a caldera that is still geologically active.
Öskjuvatn - Iceland's Deepest Lake in Askja Caldera
Iceland's deepest lake at 220 meters, filling the Askja caldera in the remote central highlands. Formed during the catastrophic 1875 eruption that triggered mass emigration to North America.
Updated February 1, 2026By the Iceland.org Travel Team
Location
Central Highlands
220 m deep · ~12 km² · F-road access only
Öskjuvatn is a lake of extremes. Sitting inside the collapsed Askja caldera at over 1,000 meters elevation in Iceland's uninhabited interior, it is both the country's deepest lake and one of its most remote destinations. The caldera formed during the devastating 1875 eruption, which blanketed eastern Iceland in ash and triggered a wave of Icelandic emigration to Manitoba, Canada. The lunar landscape was used by NASA astronauts in the 1960s to train for the Apollo moon missions. Reaching Öskjuvatn is an adventure in itself, requiring a highland-capable vehicle and a hike across a lava field.
Safety + sourcing
Last updated: 2026-02-01
This guide is for trip planning, not emergency guidance. Conditions in Iceland can change quickly—always check official alerts and road conditions before you drive or hike.
Sources to check
Formed
1875 Eruption
The caldera collapse during the eruption later filled with water over decades.
Access
F88 (4x4 Only)
Highland F-road with river crossings. Open late June to September.
What to Expect
Askja Caldera Views
Stand on the rim of a massive volcanic caldera and look down at the dark, still waters of Iceland's deepest lake. The scale is breathtaking.
Víti Geothermal Crater
Adjacent to Öskjuvatn, the Víti explosion crater holds a milky-blue warm lake. A steep trail descends to the water for those who dare to bathe.
NASA Training Ground
Apollo astronauts trained in the Askja area in 1965 and 1967 because its volcanic terrain closely resembles the lunar surface.
Lava Field Hiking
The 2.5 km walk from the parking area crosses a young lava field before reaching the caldera rim, an otherworldly experience.
Historical Significance
The 1875 eruption devastated eastern Iceland and drove roughly 20% of the country's population to emigrate, mostly to Canada.
Extreme Remoteness
No phone signal, no services, and total wilderness. The isolation and silence in the Askja area is profound and unforgettable.
Getting There
Öskjuvatn is reached via F-road F88, which branches off Route 1 east of Mývatn. The drive on F88 is approximately 100 km and takes 2-3 hours due to rough terrain and river crossings. A sturdy 4x4 vehicle with good clearance is essential. From the Dreki hut parking area, it is a 2.5 km walk across a lava field to the caldera rim. Guided super jeep day tours operate from the Mývatn area during summer and are recommended for those without highland driving experience. There are no services along the route.
Best Time to Visit
Öskjuvatn is only accessible during a short summer window, typically from late June through mid-September when F88 is open. July and August offer the best conditions and longest daylight hours. The road opening depends entirely on snow melt and river levels, so always check road.is before departing. Even in summer, temperatures at the caldera can be near freezing with strong winds, so bring warm layers and windproof clothing. The area is completely inaccessible in winter.
Planning help
Öskjuvatn FAQs
Quick answers with safety notes where it matters.