Ruokolahti is a municipality of Finland, situated in south-eastern Finland, in the region of South Karelia. Neighbouring municipalities are Imatra, Lappeenranta, Taipalsaari, Puumala, Sulkava, Punkaharju, Parikkala and Rautjärvi. Ruokolahti covers an area of 1,219.85 square kilometres (470.99 sq mi) of which 23% is water.

Imatra is a town in Finland, located in the southeastern interior of the country. Imatra is located in the region of South Karelia, on Lake Saimaa, the River Vuoksi. The population of Imatra is approximately 25,000, while the sub-region has a population of approximately 37,000. It is the 41st most populous municipality in Finland.