Nature on the Järnäshalvön

The Järnäs area is dominated by rocky terrain with pine forests and bogs in the slums, clapper fields with beach embankments and block beaches with sparse vegetation. The peninsula is located in the uplift region and houses one of the most beautifully trained coastal-type drumlin areas in the whole country. 

Drumliner and drumlinoid forms occupy a relatively large part of the Järnäs Peninsula and between them are elongated bogs. The moraine forms here reach 20–25 meters above sea level and a length of 400–2,600 meters and a width of 100–300 meters. Most drum lines have a core of visible solid rock, usually in the northern part, ie on the impact side. They extend in a north – south direction and give the landscape a characteristic appearance, which is further enhanced by the lake contours and the elongated bogs.

The drum information is also reflected in the coastal contour, which is particularly clear between Järnäsudden and Tjäruskäret. Järnäs cape is interesting from a geological point of view because the bedrock consists of ionic diabase with fl ack precipitation, which is the youngest bedrock on our coast, almost 1.2 million years old. On the headland there are also beautifully ground round slabs 10–15 meters above sea level.

The partly forested Järnäs Islands just outside the peninsula itself are a valuable breeding bird area. An inventory in 1976 counted a total of 559 breeding pairs of 19 bird species, mainly ducks and whitebirds, in an area of just under 50 hectares. A large number of birds stretch past Järnäs cape during the autumn migration. During 18 days in the autumn of 1982, more than 16,000 individuals of at least 93 species were counted.