The Sonian Forest (Zoniënwoud in Dutch) is a stunning forest to the south-east of Brussels. On foot, it is so big you can actually easily get lost in it, despite the occasional maps with You Are Here indicators. The forest is famous for its cathedral-like areas populated with majestic beeches. The forest feels almost like unspoilt, virgin forest, but it's actually mostly the result of large-scale planting of trees over a hundred years ago. Nevertheless, the presence of deer and other wildlife is enough to give it its unique wild character. The contrast with nearby Brussels couldn't be bigger, yet there's a convenient Brussels tramline which can drop you off on the Northern edge of the forest.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.