Harjukoski water mill from the 1870s and a miller’s cottage with outbuildings are in Ihastjärvi village on the shores of rapid Harjukoski between lakes Kyyvesi and Harjujärvi. The water mill with two pairs of millstones was in active use until 1975. The mill is historically valuable due to its construction technology.

About 30 km from Mikkeli.

Open summertime: During weeks 26-31 Tue–Sat 10–17.

No admission fee during opening hours.