Rantamo-Seitteli is Finland’s largest water protected wetland.
Located on the western shore of Lake Tuusula and has a total size of 28 hectares.

The Rantamo-Seittel wetland consists of two parts connected by a canal. The Rantamo wetland (8.4 ha) on the western shore of Lake Tuusulanjärvi was the first to be completed in 2001. The wetland was built in a flood-prone field along Sarsalanoja. Sarsalanoja is the largest ditch flowing into Lake Tuusula, and its water is very rich in nutrients. The ditch is heavily loaded, mainly from heavily cultivated fields and sparsely populated areas.

The Rantamo and Seittel wetlands retain about a quarter of the nutrient load from the Sarsalanoja catchment area to the lake. In addition to water protection, wetlands increase biodiversity, enliven the landscape and provide shelter and nesting sites for birds.