The base is the 1816 Treaty of Aix-la-Chapelle fixing the demarcation between the kingdoms of the Netherlands and Prussia. These markers are labelled as LBN in Geoportail, for example LBN69. Currently are only considered LBN52 to LBN75. LBN75 is labelled as LB75 (errata?); LBN55 and LBN74 could not be found in the Geoportail map. LB52 is a tripoint of Luxembourg, Belgium and Germany: Dreiländereck.

• Map
• Pictures of LBN markers in Wikipedia Commons
• Bornes frontières belgo-prussiennes
• Ancienne frontière entre la Belgique et la Prusse

Belgian, Luxembourgish and German officials at Schmëtt, a former tripoint of Belgium, Luxembourg and Germany. LB286 marker to the left, LBN75 marker to the right. Picture around 1910; same place in 2021.