|• location||Saint-Hubert, Belgium|
|Length||46 km (29 mi)|
|• average||7.4 m3/s (260 cu ft/s)|
|Progression||Lesse→ Meuse→ North Sea|
Its source is located on the plateau of Saint-Hubert. It passes through the villages of Poix-Saint-Hubert, Smuid, Mirwart, Grupont, Lesterny, Forrières, Jemelle, and the town of Rochefort, where it carved the Lorette cave. It joins the Lesse river at Éprave. It has one of the greatest drops in elevation of all rivers in Belgium. Its clear waters are home to a large population of fish, and the river is a popular location for trout fishing.