Karstula is a municipality of Finland founded in 1867. It is located in the Central Finland region. The municipality has a population of 3,625 and covers an area of 963.19 square kilometres (371.89 sq mi) of which 76.22 km2 (29.43 sq mi) is water. The population density is 4.09 inhabitants per square kilometre (10.6/sq mi).

Kyyjärvi is a municipality of Finland. It is located in the Central Finland region, about 120 kilometres (75 mi) northwest of Jyväskylä. The municipality has a population of 1,174 and covers an area of 469.61 square kilometres (181.32 sq mi) of which 21.39 km2 (8.26 sq mi) is water. The population density is 2.62 inhabitants per square kilometre (6.8/sq mi). The municipality is unilingually Finnish.