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 42nd most populous municipality in Finland. Imatra lies on the border with Russia. On the other side of the border, seven kilometres away from the centre of Imatra, lies the Russian town of Svetogorsk.