Let me explain.
Normally we take a GPS device or (at least) a map with us when going on a hike, or day tour with our car. However sometimes we forget the GPS or simply don’t have a map of the region. In that case we look around at the place we start and most of the times (especially in well known, much visited (touristic) regions) we’ll find a large (wooden) signpost with a map. Very often such maps are placed in town squares, at car parks, along (hiking) trails, at cable railway stations or at mountain cabins for example.