The 'Vennbahn' was build between 1885 and 1889. By signing the Treaty of Versailles (28-06-1919 the Bahn became part of Belgium.
During WO II the Bahn was confiscated for the Third Reich and was used for transportation of cargo and troops.
By the treaty of 1956 the Bahn was declared Belgium territory. The rails are removed and the railway is asphalted and is a 125 km. long bike path from Freistadt Achen (Adlersteine) till Troisvierges.
It's odd, left and right of the Bahn is Germany, the Bahn itselfs is Belgium territory.
Bordermarkers
Along the Bahn you'll find severall bordermarkers. Because I was just cycling and not BM-hunting ;), I just picturised some of the stones.
On some, the 'B' of Belgium pointing to the Bahn, the D of Deutschland (Germany) pointing from the Bahn to Deutschland, is good to see.