A further 26 km circuit at the GR412, for the most demanding hikers. Extending as far as Charleroi railway station, the circuit passes by particularly attractive places, such as the Marchienne and Monceau castles, the Martinet site and slag heaps and the Dampremy-La Docherie chain of slag heaps. The tour includes climbing the four slag heaps connected to each other by passages, paths
and short crossings over secondary roads. The tour is signposted with slabs recovered from a wall from the 1980s. The triangularshaped slabs evoke the shape of the slag heaps.