This is the marker that normally is covered bij a
flat-stone.
You put your business-card under it, remember.
It was in the garden of the Dutch shipping-organisation
in/near Perl.
P stands for Preußen (or Preussen) in German or
Pruisen in Dutch.
I don't know what that would be in English.
I took a photo from the other side. I think the stone has the
year 1850 engraved.
gl
Harry ten Veen
I believe this is near the France-German/Lux
tri-line or near Basel.
I'm trying to identify what the P would stand
for. Ideas?