AT A GLANCE
Why go?
Östra Nässjön (rendered in maps data as "Ostra Nassjon") is a small, clear inland lake set high in the moorland and boreal forest of Härjedalen, just outside the village of Tännäs in western Sweden. Sitting at about 780 metres above sea level with a shoreline of roughly 3.4 kilometres and a surface of some 36 hectares, it is the kind of quiet fell-edge water that draws visitors to this part of Jämtland County: unpolluted, low-traffic and surrounded by open mountain and woodland rather than resorts.↗↗
What gives the lake its character is its setting inside the Rogen Natura 2000 area, the great forest-and-fell wilderness straddling the Swedish–Norwegian border. Officially monitored water quality is rated good, with no acidification or eutrophication, so the lake reads as pristine high-country water. Its outflow, the Nässjöbäcken, threads its way downstream into the vast Dalälven catchment. For a visitor already exploring Tännäs and the Rogen country, Östra Nässjön is a peaceful stop to walk beside, cast a line or simply take in the stillness of the southern Swedish mountains.↗
A high lake in the Rogen country
Östra Nässjön is a classic Härjedalen "insjö" – an inland lake lying below the treeless plateau but well above the valley floor. Its own catchment is a patchwork of boreal forest (about a third of the area) and open mountain heath or kalfjäll (over half), the terrain that defines the Rogen region. At 780.2 metres, the water feels cooler and clearer than lowland lakes, and the short, roughly 3.4-kilometre shoreline makes it easy to circle on foot.↗
The lake is part of the Rogen Natura 2000 protected area, a designation that signals the wider landscape's conservation value rather than a fenced visitor site. In practice this means the surroundings are kept natural and undeveloped: no large-scale tourism infrastructure presses against the water, and the experience is one of quiet woodland and fell rather than manicured attractions.↗
Fishing and slow days by the water
The lake rewards those who come to fish. Register sampling has recorded perch, pike, burbot and trout in its waters, the typical mix for a Swedish upland lake of this size. Even if you are not a keen angler, the shore is a place for a slow walk, birdlife and reflection on the water's glassy surface.↗
Östra Nässjön lies within a region that takes sport fishing seriously. The broader Tännäs fishing area, a short drive away, encompasses dozens of lakes and streams and is known for varied fishing for perch, Arctic char and trout, with boat and canoe hire and a dedicated fishing centre in Tännäs village. That regional culture means local knowledge, permits and gear are easy to find, even though the fishing rights and rules for Östra Nässjön itself are governed by the water body's own management.↗
Planning a visit
Östra Nässjön is reached from Tännäs, a small mountain village on the main road through western Härjedalen, not far from the Norwegian border and the larger resort towns of the area. Treat it as a stop within a wider day of hiking, fishing or driving in the Rogen and Tännäs countryside rather than a single destination with its own ticket office or facilities.↗
If you intend to fish, check the permit and access rules for this specific water before you go, as Swedish lakes in managed fishing areas typically require a licence and may carry season or method restrictions. The staff at the Tännäs fishing centre are a good starting point for current local arrangements.↗
What makes it special
A clear, high-altitude lake (about 780 m) of roughly 36 hectares in the Härjedalen upland near Tännäs.↗
Lies inside the Rogen Natura 2000 wilderness, with water officially rated good and free of acidification or pollution.↗
Fished for perch, pike, burbot and trout – a quiet spot for angling and a short lakeside walk.↗
Base yourself in Tännäs, in a region renowned for varied mountain sport fishing.↗
A little planning goes a long way
- Pair the visit with the wider Tännäs and Rogen area: hiking, other fishing waters and the village's fishing centre and gear shops.↗
- Bring layers and good footwear even in summer – at 780 metres the high-country weather can turn cool and wet quickly.↗
- Verify current fishing-permit and access details for the lake itself before travelling with rods, since rules vary by water in this managed fishing region.↗
About this guide
Compiled with AI assistance from the sources below; this is not a first-hand visit. Place details collected October 5, 2026. Hours, access and ratings can change; confirm with the venue before visiting.
