5 / 14 Saimaa scenery Punkaharju - Rapids - Saimaa Canal - Kolovesi - Linnansaari - Olavinlinna Imatrankoski is the best-known of the rapids along the Vuoksi. It has a drop of 18 m and was one of Finland's best-known sights from the early 19th century onwards, being renowned for its wild torrent for centuries before that. The Vuoksi is the outflow channel of the Saimaa watercourse and the most voluminous river in Finland. It begins at Vuoksenniska in Imatra and flows into Lake Ladoga 140 km downstream. Only 13 km of this distance lies within the borders of Finland today. The Vuoksi remained unharnessed until the construction of the first power plant at Tainionkoski rapids in the upper reaches of the river in 1924. Imatra rapids are allowed to run free for a while every day in summer Imatrankoski is the best-known of the rapids along the Vuoksi. It has a drop of 18 m and was one of Finland's best-known sights from the