Nuuksio National Park is the closest one to Helsinki. This route is accesible with public transport with the bus 345 that leaves from the central station in Helsinki. The route goes through wide and narrow trails, very often it gets lost, and is easy to take the wrong path. Therefore, map and navigation system are required. The route also crosses a small river without bridge, and it is very probable that it has snow and ice until May. However, there are no technical risks if doing it in the summer.