Historical Partakoski is located about 9 km from the church village of Savitaipalee, on the narrow isthmus between Lake Saimaa and Kuolimo. Partakoski is the common name for three separate areas Ahvenkoski, Saunakoski and Siikakoski. Partakoski and Kärnäkoski are the estuaries of the Kuolimo estuary. They connect Kuolimo with Saimaa. Partakoski is a rapids route of almost a kilometre in length, including three fjord sections. Partakoski is the only spawning ground for lake trout in the southern Saimaa area.