Silva Carbonaria, the “charcoal forest”,[1] was the dense old-growth forest of beech and oak that formed a natural boundary during the Late Iron Age through Roman times into the Early Middle Ages across what is now western Wallonia. The Silva Carbonaria was a vast forest that stretched from the rivers Zenne and the Dijle in the north to the Sambre in the south.[2] Its northern outliers reached the then marshy site of modern Brussels.[3]

Source: Silva Carbonaria – Wikipedia