Hi Carnildo, its it’s still in use as man-made=survey_point, the american American long straight border lines are based on these points. Since its it’s historical to, it could be a United States National Historic Landmark, Landmark; the heritage tag could be added as well. The historic_boundary_stone is IMHO more like the Wiki picture 4, https://wiki.openstreetmap.org/wiki/Key:historic. And you example is a kind of "hidden" but secure surveypoint.survey point, but your picture could be a short pole as well, but this one would have a foundation. The single ones like picture 4 would have a certain size but no foundation.

Hi Carnildo, its still in use as man-made=survey_point, the american long straight border lines are based on these points. Since its historical to, it could be a United States National Historic Landmark, the heritage tag could be added as well. The historic_boundary_stone is IMHO more like the Wiki picture 4, https://wiki.openstreetmap.org/wiki/Key:historic. And you example is a kind of "hidden" but secure surveypoint.