These 50 images are my impression of the "Boucle Noire" hike, north-west of Charleroi. The "Boucle Noire" is a variation of GR-412 ("Le Chemin des Terrils").
It consists of +23 kms worth of hiking over terrils, alongside canals and the river Sambre, and experiencing the remnants of an industrial and coalmining past. Great stuff.
More info : https://cheminsdesterrils.be/2016/08/02/la-boucle-noire-du-gr-412/