Hello.
On the detailed map that Jesper provided some time
ago, border markers are shown as circles.
At the Dreilaennereck it says: Bnes 1. That means
Bornes 1, also Border markers #1. So there are more than one, probably two
markers.
The borderline indicates two circles very close
together, the one almost covering the other.
Therefore in my opinion the border is in the middle
of the stream as is indicated bij two border markers # 1.
Also look on the webpage of Jannis Deeleman and Eef
Berns:
They also heve the names of te
streams!
Indeed BE/FR markers are stone blocs. See for
example on the site of Louis Fierens:
Groeten en suc6
Harry ten Veen