Odo: 284725 Location: Pyhä-Häkki National Park / Finland
In Germany all national park visits start with a sign of what is not allowed. No camping, no fires, no picking mushrooms or berries, no fishing, … They try to spoil the experience as good as they can so most people drive there, walk for a couple of hours and then drive back to their home/hotel. There are some small shelters against the rain sometimes which you can misuse for staying overnight.
In Finland there are also signs at the park entrance, for example: Camping and fires are only allowed in the designated areas (see map just aside the sign), picking mushroom, berries is allowed throughout the park as well as fishing. The tracks are well marked and maintained, it is really difficult to get lost. I once did because a sign pointed in the wrong direction. I also really like their take on “designated area for fires”: