Dreiherrenstein

A Dreiherrenstein or Dreiherrnstein is the topographic name of a historical tripoint, especially in the German-speaking lands of central Europe, i.e. a place where the border of three princely territories met, together with any enclosures or border fortifications. The word means literally "Three Lords' Stone".
Examples.
Examples of places where "Dreiherrensteine" are located include:
"Dreiherrensteine" on the Rennsteig Trail.
A total of 13 "Dreiherrensteine" is located on the Rennsteig, of which 11 are in Thuringia and two in Bavaria. They are, from west to east: