The Semois (or Semoy for its part flowing in France; Setzbaach in Luxembourgish in the Pays d'Arlon; Sesbach in German; Simwès in Walloon, often elided in Smwès) is ariver deBelgium et deFrance,tributary  on the right bank of theMeuse. It takes its sources fromArlonin Belgium, crosses theGaume and theArdennes  following a west-northwest direction, crosses thefrench borderand flows into the Meuse atMontherme. It crosses Chiny and runs along the Le Canada campsite.

The partWalloonof the Semois valley was renowned in the 20th century for itstobacco  (to roll or pipe).

Semois tobaccos are dark tobaccos with very particular aromas, due to the climate of the Semois valley and to a particular elaboration. However, production has slowed down considerably and is now reduced to a few producers.

The Semois has its source in the town ofArloninBelgium, in the basement of Sonnetty Street. She then heads for theGaume  which it crosses and which constitutes the major part of its journey, to enterArdennes. She will have crossed among other thingsForks,Sampont,Stall,Tintigny,China,The kitchen,Florenville,Herbeumont,Cugnon,Auby-sur-Semois,Dohan,Broth,Poupehan,Frahan,Vresse-sur-Semois etBohan.

She comes intoFrance  near the village ofThe Upper Riversto jump into theMeuse atMontherme, 10 km after leaving Belgium.

Its course, in an overall west-northwest direction, totals 210 km, including 200 in Belgium and 23.6 km in France. She forms manymeanders, the confluence with the Meuse being only 80 km as the crow flies from its source.