The forest is in the Flemish parts of Sint-Genesius-Rode, Hoeilaart, Overijse and Tervuren, Uccle , Watermael-Boitsfort, Auderghem and Woluwe-Saint-Pierre in the Brussels-Capitale Region and in the Walloon towns of La Hulpe and Waterloo. Thus it stretches out over the three Belgian Regions. It used to be connected with Bois de la Cambre and Hallerbos (Blue Forest in Belgium) but they split up in 1900.