Sillon industriel

The Sillon industriel (French: [sijɔ̃ ɛ̃dystʁijɛl], "industrial furrow") is the former industrial backbone of Belgium. It runs across Wallonia, passing from Dour, the region of Borinage, in the west, to Verviers in the east, passing along the way through Mons, La Louvière (Centre-region), Charleroi (Pays Noir), Namur, Huy, and Liège. It follows a continuous stretch of valleys of the rivers Haine, Sambre, Meuse and Vesdre, and has an area of roughly 1000 km².

The strip is also known as the Sambre and Meuse valley, as those are the main rivers, or the Haine-Sambre-Meuse-Vesdre valley, which includes two smaller rivers. (French: sillon Sambre-et-Meuse or sillon Haine-Sambre-Meuse-Vesdre). It is also called the Dorsale wallonne, meaning "Walloon [industrial] backbone".

It is less defined by physical geography, and is more a description of human geography and resources. As heavy industry is no longer the prevailing feature of the Belgian economy, it is now more common to refer to the area as a former industrial belt.

Around two-thirds of the population of Wallonia lives in the area – over two million people. Its main stretch is sometimes called the Charleroi-Liège valley, which connects Charleroi and Liège. Some see it as a Walloon metropolis, although it is linear rather than multi-directional sprawl.

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