If the shelter is free, you are welcome to stay overnight in it, but if you want to be on the safe side, we recommend booking in advance.
You can book a shelter on the Danish Nature Agency's website
Birkelunden Camp site, camp site with 3 shelters and space for tenting. On the site there is drinking water and mud toilet, campfire site and drinking water: https://udinaturen.dk/shelter/5429
Badesøen shelter, primitive accommodation with 1 shelter: https://udinaturen.dk/shelter/4778
Tent site Himmerigsvejen, small tent site: https://udinaturen.dk/shelter/103034
Tent site Vestre Skråvej, primitive overnight site for a few tents:https://udinaturen.dk/shelter/103035