If this was in Germany, there would be a fairly high precision map somewhere that records the intended position of each marker stone. This is usually the case f

If this was in Germany, there would be a fairly high precision map somewhere that records the intended position of each marker stone. This is usually the case for demarcations between private properties. If one of them gets moved, surveyors get sent out to measure the proper location from the map data and surrounding markers. And there's usually a fine for whoever moved such a stone.