Lake Siljan

Lake Siljan



Location: Dalarna province   Map

Area: 354 km²

Depth: 120 m


Description of Lake Siljan

Lake Siljan, in the Dalarna region of central Sweden, is the sixth largest lake in the country. The accumulated area of ​​the lake and of all the small adjacent lakes (especially Orsasjön and Insjön) is 354 km². Its maximum depth is 120 m, and its altitude is 161 meters above sea level. The biggest city on its banks is Mora, being others of the ring of Siljan, Leksand, Orsa, Rättvik and Boda.


The lake is located on the southwestern perimeter of the Siljansringen (ring of Siljan), a circular geological formation that was formed 377 million years ago in the Devonian by the impact of a large meteorite. The original crater, now mostly eroded, is estimated to be about 52 km in diameter and is the largest known impact crater in Europe (excluding Russia). The sedimentary layers of the Cambrian, Ordovician and Silurian periods in the area contain important amounts of fossils. There are suspicions of the existence of oil, but the investigations so far have yielded negative results. There are large deposits of lead and zinc in the area.



365 million years ago, a meteorite struck with enormous force and formed what is today called the Siljan Ring. Siljan, Orsasjön, Skattungen, Oresjön and the small lakes in Bodadalen are the meteor crater's outer ring.

The crater measures 50 km in diameter, maximum depth 160 m, and is the largest known impact site in Europe.

Österviken was later formed as a glacial valley in a southerly direction during the last ice age.


The Siljan area

The area consists of Siljan's and Orsasjön's water system with connecting terrain, as well as the area along Siljansringen. The bedrock around Lake Siljan consists, in addition to the Precambrian bedrock, of sedimentary rocks from mainly the Ordovician and Silurian.

These were set on edge at the meteorite impact that formed Siljan and are therefore preserved today. The area is a type area for many fossils and therefore geologically important from a global point of view. There are many active and closed quarries in the area. An example of a disused quarry that has come to life again is Dalhalla outside Rättvik.

Within the area there is an extensive network of hiking and biking trails, as well as ski trails. Siljansleden comprises 340 km of hiking trails in alternating countryside and uninhabited, mostly following the old summer pasture paths and with rest areas and overnight cabins in suitable places. Bathing places are found around the whole of Lake Siljan and Lake Orsa. As an outdoor and recreational area, the Siljan region has a long history. Early on, health wells and open-air baths were built in the area. The Siljan area is visited annually by hundreds of thousands of people. Both Sollerön and Skattungen are part of the Siljan area and are of national interest for outdoor life. Gesunda Bay is also interesting for outdoor life. In the Siljan area, there is also the country's oldest local radio station that still broadcasts locally, Radio Siljan. They broadcast daily all year round and provide tourists in the area with valuable tourist information.

Ancient remains on Sollerön from the latter part of the Iron Age (Viking Age).