LorenzI just discovered a wonderful website to view free camping sites on a map, based on open street map data:
MarieLouise@l0drex Not all of the sites on this map are free. In my neighbourhood I see several campsites but none of them are free. On the contrary, they’re quite expensive!
@MarieLouise Yes, it shows all campsites by default. But you can enable a filter to only show free campsites. Sorry!