Tervo is a municipality of Finland. It is located in the province of Eastern Finland and is part of the Northern Savonia region. The municipality …Tervo is a municipality of Finland. It is located in the province of Eastern Finland and is part of the Northern Savonia region. The municipality has a population of 1,400, making it Northern Savonia's least populous municipality. It covers an area of 494.30 square kilometres of which 146.52 km² is water. The population density is 4.03 inhabitants per square kilometre.