The river rises in the eastern
Ardennes and western
Eifel on Belgian soil. Its source near
Losheimergraben lies northeast of the
Eichelsberg mountain (653 m) at 643 m, near the B 265. Just a few hundred metres away is the source of the
River Kyll. The Our initially follows the B 265, also the Belgian–German border. From the
tripoint by the Europa Monument between
Ouren (Belgium),
Sevenig (Germany), and
Lieler (Luxembourg), it runs almost entirely on the German–Luxembourg border until Wallendorf. It generally
meanders from north to south. For the section along the German–Luxembourg border, the Our is a jointly managed
condominium (the "Joint German–Luxembourg Sovereign Area"). Unilateral sovereignty begins only at the respective shore. In the upper reaches between Germany and Belgium, the border lies on the
thalweg. ==Tributaries==