Nature trails on the map: over 600 short marked routes in Finland, suitable for families, by municipality. Free, no registration needed.
644 places in
Most nature trails are in Jyväskylä (22), Espoo (18) and Kemiönsaari (14). The full list is below by municipality, and the map can be filtered to your own area.
The remaining places are on the map and in the municipality list.