You have a legal right to walk, cycle, paddle a canoe or even camp almost anywhere in Finland.
Nordic skiing is popular and there are cross-country trails of varying difficulty.
Downhill skiers go to Lapland, or to resorts such as Koli in North Karelia or Ruka in Kuusamo. Wilderness huts line the northern trails and are available without charge. Most of them have unlocked doors, basic bunks, cooking facilities, leftover dry food, a pile of dry firewood and even a wilderness telephone. You should always leave the hut as it was - replace the used firewood and clean the place. For the easiest hikes, go to areas such as Ruunaa in Karelia or try a national park.