1) The Saimaa Cycling Route runs through Ruokolahti, Taipalsaari, Lappeenranta, Joutseno and Imatra. Length 156 km. See more on the dedicated Saimaa Cycling Route -page or on separate cycling pages here.
2) The Four Island Cycling Route takes you through beautiful archipelago sceneries in Imatra and Ruokolahti, 52 km. See more info here.
3) South Karelia Cycling Routes in Google Maps