Camping is generally permitted for a couple of nights almost anywhere in Finland, except in the vicinity of homes, in cultivated fields and nursery plantations, or in certain areas such as nature reserves and most parts of national parks.
Shelters and daytrip cabins are mainly intended for picnics, but hikers may stay overnight in such facilities in emergencies.
Wilderness huts are located in remote areas, such as the national parks and wilderness areas of northern Finland. Anyone may stay in open wilderness huts, which typically have very few facilities - only a stove and a couple of pans - but are safe places for up to ten people to sleep on simple wooden bunks. Some huts may get crowded during the peak season (late June - early Sept). Reservable wilderness huts can be booked for short stays in advance for a few euros per night, through local nature centres. These huts are locked, and usually have blankets and mattresses as well as a stove. See the web pages for specific destinations for details of local wilderness huts. Many larger wilderness huts have reservable and open sections.
Accommodation in cabins, cottages, farmhouses and youth hostels is widely available in most parts of Finland, although it can be hard to find such accommodation in or within walking distance of national parks. See the web pages for specific destinations or local tourist offices for details of local accommodation.