Iitti (; ) is a municipality of Finland. It is located in the province of Southern Finland and is part of the Päijänne Tavastia region. The municipality has a population of () and covers an area of of which is water. The population density is . The administrative center of Iitti is in the village of Kausala. Neighbour municipalities are Heinola, Kouvola, Lapinjärvi, Lahti and Orimattila. The municipality is unilingually Finnish. In 1990, the center of Iitti, which surrounds the old parish church, was voted the most attractive kirkonkylä ("church village") in Finland. The Kymi Ring motor sport center is located in Iitti, right next to the border of Kouvola. History The surroundings of lakes Urajärvi and Pyhäjärvi have been known to be exploited as wilderness since the Stone Age, although no signs of permanent habitation from the era have been found, and the area is presumed to have been entirely uninhabitated in the interim between the Stone Age and the conversion of Finland to Christianity. By the end of paganism, Iitti had gained its first permanent inhabitants first from Hauho and Vanaja, as well as later on from Hollola. The oldest village in Iitti is presumed to be Kauramaa, though several others are mentioned in documents dating to the Middle Ages. Administratively, Iitti was a chapel subordinated to the parish of Hollola until 1539, after which it became an independent parish that also included Nastola, Jaala, Valkeala and parts of Mäntyharju, by proclamation from Gustav I. At this time, Iitti had 14 villages and 89 estates. Iitti suffered greatly over the Russo-Swedish War of 1788–1790, becoming a battleground as well as a headquarters for Swedish forces. The battle of Tillolankangas was one of the bloodiest over the entire war in Finland; the Swedes' victory cemented the liberation of the villages around river Kymi. Over the course of the war, 13 villages were destroyed in Iitti. Until 2021, Iitti was part of the Kymenlaakso region before it became part of Päijänne Tavastia. Geography Villages In 1968, Iitti had the following villages: Haapakimola Kauramaa Kausala Kimola Iitti Koliseva Koskenniska Lyöttilä Kymentaka Muikkula Niinimäki Perheniemi Radansuu Saaranen Sitikkala Säyhde Sääskjärvi Taasia Tapola Vuolenkoski Demographics In 2020, 14.0% of the population of Iitti was under the age of 15, 55.2% were aged 15 to 64, and 31.5% were over the age of 64. The average age was 48.8, above the national average of