Þjórsárdalur
About Þjórsárdalur
Þjórsárdalur is a valley in South Iceland beside the Þjórsá, the country's longest river, running up from the farmland around Árnes toward the edge of the Highlands near Hekla. Much of the valley floor is black pumice and gravel left by eruptions, broken up by birch woods, rhyolite hills and a run of waterfalls. It is about two hours by car from Reykjavík, and few places in the south pair waterfalls with Viking-age history so neatly.
Before 1104 about 20 farms stood in Þjórsárdalur. That year Hekla erupted and buried the valley in a thick layer of pumice, and most of it was abandoned for good. The ash that ended those farms also preserved them, which is why the valley holds one of the best-known archaeological sites in Iceland.
That site is Stöng, a chieftain's farm near the head of the valley, excavated in 1939 by a team of Nordic archaeologists in one of the first scientific digs in the country. Under a protective shelter you can walk around the stone footings of the longhouse and its side rooms, with a small church site nearby. The shelter first went up in 1957 and was extended and restored in 2024, with better paths and new information panels.
The waterfalls are the valley's other draw. Hjálparfoss, a double fall framed by curved basalt, sits on a short spur off Route 32, while Háifoss drops 122 meters into a canyon at the end of rough Road 332. Gjáin, a green hollow of small falls and lava formations, lies a 15-minute walk from the Stöng parking lot, and back near Route 32 the reconstructed Þjóðveldisbærinn farm shows how Stöng looked before the eruption.
Route 32 is the main road up the valley, but the side roads to Stöng, Gjáin and Háifoss are gravel, bumpy after rain and best driven in a 4x4. June to September is the time to go, when those roads are in their best shape and the moss and birch are green. Give the valley a full day if you want to see everything without rushing, and check the road conditions map before you turn off Route 32.
Good to know
Where is Þjórsárdalur?
Þjórsárdalur is a valley in South Iceland beside the Þjórsá river, running northeast from Árnes toward the Highlands near Hekla. Route 32 is the main road through it.
How do you get to Þjórsárdalur from Reykjavík?
Drive Route 1 toward Selfoss, then Route 30 and Route 32 into the valley. The trip takes about two hours, and the gravel side roads to Stöng and Háifoss add more time.
What is Stöng in Þjórsárdalur?
Stöng is the ruin of a chieftain's farm that Hekla buried in 1104, excavated in 1939 and now protected under a shelter that was restored in 2024. You can walk around the stone footings of the longhouse and its side rooms.
Do you need a 4x4 in Þjórsárdalur?
Not for Route 32 or Hjálparfoss, but the gravel roads to Stöng, Gjáin and Háifoss are rough and a 4x4 is the safer choice, especially after rain.
What waterfalls are in Þjórsárdalur?
The main ones are Háifoss, at 122 meters one of the tallest in Iceland, its neighbor Granni, the double fall Hjálparfoss and the small falls of the Gjáin valley.
When is the best time to visit Þjórsárdalur?
June to September, when the gravel roads are in their best shape and the valley is green. In winter the side roads to Stöng and Háifoss can be hard going or impassable.
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