Surface Area
~88 km²
Iceland's largest body of water by surface area after reservoir expansion.
Þórisvatn: Iceland's Largest Reservoir and Highland Lake
Iceland's largest body of water at approximately 88 km², a highland reservoir in the treeless central interior. Enlarged for hydroelectric power and home to trophy brown trout.
Location
Central Highlands
~88 km² · Elevation ~570 m · F-road access only
Þórisvatn is a large highland lake in Iceland's remote interior, originally a natural lake that was expanded through damming in the 1970s to serve the Búrfell hydroelectric power station. At roughly 570 meters above sea level, the lake is surrounded by barren, windswept highlands with glaciers on the horizon. Almost nothing grows here, and the solitude is the kind that defines the Icelandic interior.
Sources and last reviewed
Last reviewed: 2026-03-03
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.
Pages are reviewed for practical usefulness, source quality, and volatile claims before publication.
Official sources to check
Primary Use
Hydroelectric Power
Feeds the Búrfell power station via the Þjórsá river system.
Access
4x4 Required
Highland F-roads only. Typically open late June to September.
What to Expect
Remote Highland Wilderness
This is Iceland's interior at its emptiest. The landscape is barren and vast, with no trees, buildings, or signs of habitation.
Trophy Brown Trout Fishing
The lake is known among anglers for large brown trout. Permits are required and catches of 5+ kg fish are not uncommon.
Glacial Panoramas
On clear days, views extend to the Hofsjökull and Vatnajökull glaciers.
Hydroelectric Heritage
The dam and infrastructure show how Iceland harnessed its glacial rivers for renewable energy.
Birdlife on the Shores
Despite the remote location, the lake attracts birds including great northern divers and wading species during summer.
Midnight Sun Solitude
In June and July, the midnight sun lights the landscape around the clock, so you can explore at any hour.
Getting There
Þórisvatn is accessible via highland F-roads from the south, typically via the Sprengisandur route (F26) or from the Landmannalaugar area. A sturdy 4x4 vehicle is essential as the roads involve river crossings and rough terrain. The lake is approximately 200 km from Reykjavik as the crow flies, but the drive takes significantly longer due to road conditions. Highland roads are generally open from late June to September depending on weather. There are no fuel stations or services in the highlands, so bring all supplies.
Best Time to Visit
Þórisvatn is only accessible during summer when highland roads are open, typically from late June through September. July and August offer the best conditions with relatively mild weather and the longest window of accessible roads. Early summer brings midnight sun and the start of the fishing season. September can offer early northern lights but roads may close unpredictably due to early snowfall. Always check road.is for current highland road status before departing.
Planning help
Þórisvatn FAQs
Quick answers with safety notes where it matters.