‘Lapp cairns’ are ancient ritual/burial cairns mostly constructed 3000-4000 years ago.
There is a Lapp cairn only about 2km boat-trip away from the cottage. It is on the Linnasaari ("Fort Island") island and can be reached in 15 minutes. The island is over one kilometer long so there are a variety of places where you can go ashore. One good location to go shore is just opposite of the pier for Pieni Linnasaari ("Small Fort Island") which has a campfire place and dry-toilet. It is sheltered from larger waves and already at the north side of the island where the Lapp cairn is also located. You can find the Lapp cairn north, on the highest point of the island. It is a large heap of boulders which have been carried there by hand thousands of years ago. There are no cottages/buildings on the island.
Multiple Lapp cairn have been found in the Finnish Lake District. They have been researched and documented for a long time but it is still not fully known who, why and when build the Lapp cairns.
The archaeological journal "Iskos" (Ed. 25, published in 2023) describes Lapp cairns:
Lapp cairns are typically located on elevated bedrock sites along lakeshores. The most typical Lapp cairn find contains a small amount of burnt human bone, but it is not present in all Lapp cairns. Other finds include quartz and flint flakes, animal bone and occasional metal or stone objects.
Lapp cairns resemble contemporary cairns in coastal Finland but are surrounded by dwelling sites, suggesting mobile fisher-huntergatherer lifeways, in contrast to more sedentary and agricultural life around the coastal cairns.
Cremation and the dispersal of burnt human bone above ground also had local roots in eastern Fennoscandia. An essential aspect of the Lapp cairn tradition was its close connection to the labyrinthine lakescape of the Lake District. Lapp cairn sites were invariably surrounded by rock and open water on several sides. The builders of the cairns most likely saw the natural environment around them as inhabited by invisible forces with whom they needed to communicate ritually.
[Source: https://journal.fi/iskos/issue/view/9179 - Free to download]