Depth
220 meters
a deep crater lake, filling a caldera that is still geologically active.
Öskjuvatn: Askja’s Crater Lake, in the Askja Caldera
a deep crater 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.
Location
Central Highlands
220 m deep · ~12 km² · F-road access only
Quick Answer
Öskjuvatn fills the Askja caldera in Iceland's central highlands and is a deep volcanic lake. Formed after the 1875 eruption; F-road access only.
Öskjuvatn sits inside the collapsed Askja caldera at over 1,000 meters elevation in Iceland's uninhabited interior. Reaching it takes a separate highland excursion. The caldera formed during the 1875 eruption, which blanketed eastern Iceland in ash and triggered a wave of Icelandic emigration to Manitoba, Canada. NASA astronauts trained in this lunar-like landscape in the 1960s to prepare for the Apollo moon missions. Reaching Öskjuvatn requires a highland-capable vehicle and a hike across a lava field.
Sources and page update
Updated: 2026-09-10
This guide is a travel-planning summary, not emergency guidance. Conditions in Iceland can change quickly; check official alerts, roads, and weather before driving, hiking, or booking around volatile conditions.
For sourcing standards and how to report an error, see the editorial policy.
Official 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 the volcanic caldera and look down at the dark, still waters of a deep crater lake.
Víti Geothermal Crater
Adjacent to Öskjuvatn, the Víti explosion crater holds a milky-blue warm lake. The descent has separate slipping, rockfall and hot-mud hazards.
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.
Historical Significance
The 1875 eruption devastated eastern Iceland and contributed to emigration to North America.
Extreme Remoteness
No phone signal, no services, and total wilderness. Few places in Iceland are as isolated or as quiet.
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 have 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. Winter access requires separate specialist arrangements; the summer road itinerary does not apply.
The easy approach rating does not cover every descent
The park’s A1 Vikraborgir–Öskjuvatn page rates the approach easy but separately warns that the descent into Víti is slippery and subject to rock and mud slides. Do not transfer the approach rating to the crater descent.
Öskjuvatn and Víti are separate waters. A photograph of someone bathing in Víti does not establish safe access today or permission to enter Öskjuvatn. Ask the ranger about the exact route and stay behind any closure. The Askja guide explains the dated monitoring update separately from visitor access.
Planning help
Öskjuvatn FAQs
Quick answers with safety notes where it matters.
How deep is Öskjuvatn?
Öskjuvatn is a deep crater lake at approximately 220 meters. The lake fills a caldera that collapsed during the catastrophic 1875 eruption of Askja volcano, and its depth continues to be studied as the caldera slowly evolves.
Can you swim in Öskjuvatn?
Swimming in Öskjuvatn is extremely dangerous and strongly discouraged. The lake water is cold even in summer, the shores are steep and unstable, and landslides have occurred. In 1907, two German scientists disappeared in the lake under mysterious circumstances. Adjacent Víti is a separate crater; its slippery descent is subject to rock and mud slides. Ask the ranger about current access.
How do I get to Öskjuvatn and Askja?
Askja is reached via highland F-road F88, which requires a sturdy 4x4 vehicle and river crossings. Opening depends on road and snow conditions. From the Askja parking area, it is about a 2.5 km walk to the caldera rim and down to Öskjuvatn and Víti crater. Guided super jeep tours are also available from Mývatn.
What is the Víti crater next to Öskjuvatn?
Víti (meaning 'Hell') is a smaller explosion crater adjacent to Öskjuvatn, about 150 meters in diameter. It contains a milky-blue geothermal lake with variable water temperatures. The steep trail down to the water can be slippery. Víti was formed during the same 1875 eruption that created Öskjuvatn.
Country reference: Iceland statistics.