 It has two headstreams (the "Sarre Rouge" and "Sarre Blanche", which join in Lorquin), that both start near Mont Donon, the highest peak of the northern Vosges.After (126 kilometres in France and 120 kilometres in Germany) the Saar flows into the Moselle at Konz (Rhineland-Palatinate) between Trier and the Luxembourg border.It has a catchment area of .