The small forest lake Stensvattnet, just north of the village Bjärten, is considered the source of the Ledu River. On its way down to the sea, the river fl drains your lakes. In Bjärtsjön there are a number of islands that are worth a visit. One of them is Granholmen, where an old catch pit can be seen, and on a wall in Långviken you can study the inscription “Finlandia” in Cyrillic letters. It is probably people with a Russian background who have lived there and expressed their origin - and perhaps homesickness. From the 18th century onwards, the Ledu River has been a source of life and work along the valley. During the heyday of the ironworks in Olofsfors, charring in the forests around it was a vital industry. Remains of coal bottoms can still be seen everywhere in the landscape. The mill's stronghold was, of course, the blast furnace in Olofsfors. But also upstream there were forges that contributed to the great successes of the industry from the end of the 18th century to the middle of the 19th century.
At the beginning of the 20th century, Leduån's hydropower was used for electricity production. A power plant was built in Leduåfors, which supplied electricity to the mill as well as Nordmaling and Levar. It was in 1913 that Nordmaling also gained access to the new technology and in connection with this, the first outdoor lighting could also be installed. In the lakes in the water system, there is plenty of perch, pike, lake, roach, vendace and smelt. Due to the interventions made in the Ledu River at the beginning of the 20th century, salmon and trout can no longer migrate from the sea to playgrounds in the river. The trout trunks that now exist are thus stationary.