Tar was one of Finland’s most important export products from the 1500s until late in the 1800s, and Kainuu was Finland’s most important tar region. Tar was transported by narrow tar boats through rivers, lakes and rapids from Kainuu to Oulu, where tar barrels were loaded onto ships to be transported to buyers around Europe.
The large rapids of the River Kajaaninjoki, Koivukoski and Ämmäkoski were the biggest obstacles faced by the tar rowers transporting the tar loads to Oulu. To make this journey run more smoothly, the tar boar canal was built in 1847.
A tar rowing show organised in July is a unique event in which the canal locks are opened and the tar boats row through the dams to the sounds of accordion music.