Temperature
~22°C
Lukewarm geothermally heated crater water
Víti Crater at Askja: Milky-Blue Volcanic Crater Lake
A warm milky-blue crater lake formed by the 1875 eruption, deep in the Icelandic Highlands.
Location
Highlands
Askja Caldera • F-road access
Quick Answer
Víti at Askja is a milky-blue crater lake formed in the 1875 eruption, with water around 22°C. Access is by highland road F88, 4WD only, in summer.
Víti (meaning "Hell") is a geothermal crater lake inside the vast Askja caldera in Iceland's remote central highlands. Formed during the 1875 eruption that sent ashfall across Scandinavia, the crater is about 150 meters in diameter and filled with milky-blue, mineral-rich water warmed to around 20–25°C. Askja sits beside Öskjuvatn, one of Iceland's deepest lakes. The area served as a training ground for Apollo astronauts in the 1960s due to its lunar-like terrain. Access is via the challenging highland road F88, open only in summer.
Sources and page update
Updated: 2026-09-10
Ask park rangers about current access and bathing restrictions. The descent into the crater is steep and slippery. F88 requires a 4WD with river crossing capability.
For sourcing standards and how to report an error, see the editorial policy.
Official sources to check
Access
F88
Highland road; 4WD required, summer only
Formation
1875
Formed during the Askja eruption
What to Expect
Milky-Blue Crater Lake (~22°C)
The 150-meter diameter crater is filled with milky-blue water at approximately 20-25°C, rich in dissolved silica and sulfur minerals
1875 Eruption History
Formed by an eruption that sent ashfall across Scandinavia. The ashfall drove a wave of emigration from Iceland to North America
What to Bring
Sturdy hiking boots (steep loose-gravel descent), warm waterproof layers, water, and food. No facilities at the crater. Ask rangers about current restrictions
Apollo Training Site
NASA astronauts trained in the Askja area in 1965 and 1967 to prepare for the moon, drawn by the barren, volcanic, lunar-like terrain
Free Admission
No entrance fee. Access is via F88 (4WD required) plus a 2.5 km walk from the parking area
Steep Crater Descent
The path from the rim down to the water is steep and composed of loose scree. It takes 10-15 minutes down and longer back up. Use caution on the slippery surface
Getting There
From Route 1 near Lake Mývatn, take highland road F88 south for approximately 100 km (2-2.5 hours). A high-clearance 4WD is essential, with several river crossings along the way; some can be deep after rain. The nearest town with services is Reykjahlíð (100 km). From the Askja parking area, it is a 2.5 km walk across a lava field to the Víti crater rim (30-40 minutes). There is a basic toilet at the parking area but no other facilities. Guided day tours depart from Mývatn and Akureyri during summer and handle the driving. The total round trip from Mývatn is a full day (10+ hours).
Best Time to Visit
July and August only, when F88 is open and conditions are most favorable. Late June: the road may just be opening, so check road.is daily. River crossings can be dangerously high from snowmelt. July: the most reliable month with the best weather and longest daylight (near 24-hour sun). August: access remains good but daylight begins shortening. Early September: the road may close depending on early snowfall. Highland weather changes rapidly; temperatures can drop below freezing even in summer. Bring warm waterproof layers, hat, and gloves regardless of the forecast. Always check road.is and safetravel.is before departure.
Separate the crater walk from the descent
The park’s A1 route begins at Vikraborgir, where there are toilets, and leads toward Víti and Öskjuvatn. Its easy hiking rating applies to that route; the park separately warns that descending into Víti is slippery and exposed to rock and mud slides. In summer, rangers at Drekagil and Herðubreiðarlindir can advise on conditions. Plan to see the crater from above if descent is unsuitable.
Planning help
Víti Crater FAQs
Quick answers with safety notes where it matters.
Can I swim in the Víti crater at Askja?
Do not assume that bathing is possible on your visit. Ask the park rangers about current restrictions before descending. The park warns of a slippery slope, rock and mud slides, and hot mud on the bottom, particularly along the eastern bank. The lake is more than eight metres deep at its centre; an average water temperature does not describe every spot.
How do I get to Askja and Víti?
Askja is reached via highland road F88 from Route 1 near Mývatn. A high-clearance 4WD is required, and river crossings are involved. The road typically opens in late June or July. The drive from Mývatn takes about 2–2.5 hours each way.
How warm is the water in the Víti crater?
The park says the water is usually above 20°C, with temperature varying with spring meltwater. Mud on the bottom can be hot, especially on the eastern bank. This is not a uniformly heated swimming pool.
Can I visit Askja as a day trip?
Yes, but it is a long day. From Mývatn, expect 2–2.5 hours driving each way plus time at the site. Guided tours from Mývatn and Akureyri are available and handle the challenging driving conditions for you.
Country reference: Iceland statistics.