marker points into nowhere so note could be solved anyway ;) ;) ;) - But you probably mean "Schavener Heide" - you're wrong! https://www.openstreetmap.org/way/232126185 - a lot of informations are already tagged. Most of the time visitors can walk here BUT it is still a "Standortübungsplatz" and "Militärisches Sperrgebiet" - look here: https://www.mechernich.de/tourismus-freizeit/sehenswert/natur-nationalpark/schavener-heide