Sonian Forest

The Sonian Forest  is a 4,421-hectare (10,920-acre) forest at the southeast edge of Brussels.

The forest lies in the Flemish municipalities of Sint-Genesius-Rode, Hoeilaart, Overijse, and Tervuren, in the Brussels-Capital Region municipalities of Uccle, Watermael-Boitsfort, Auderghem, and Woluwe-Saint-Pierre, and in the Walloon towns of La Hulpe and Waterloo. 

Inscribed as a UNESCO World Heritage Site

Today the forest consists mainly of European beeches and oaks