Sonian Forest (Zoniënwoud) in Brussels 2024-2025

The Sonian Forest (or Zoniënwoud in Dutch) is an old beech and oak forest in the vicinity of Brussels, namely—at its southeast edge. Being the largest green area in the city, the forest is often called “Brussels’ Lungs.” Indeed, the territory of Zoniënwoud is huge—it occupies an area of 4,400 ha (10,900 ac). However, it was three times bigger two centuries ago.

The reduction of the forest’s size has influenced its ecosystem and led to the extinction of some plant and animal species. Even though the variety of flora and fauna is not as rich as it used to be, Zoniënwoud is a habitat for numerous mammals. Thus, it is a great place to spot badgers, deer, bats, red squirrels, foxes, wild boars, and fire salamanders.

Around 70% of the forest consists of beech trees with some of the oldest being over 200 years old. The vast tree crowns give shelter to a wide range of birds. While walking in the forest, you may encounter birds such as the honey-buzzard, nuthatch, short-toed treecreeper, great spotted woodpecker, goldcrest, kingfisher, and winter wren.

The forest may be visited all year round. The best time depends on your favourite season. From March to April, toads, frogs, and newts occupy ponds in the forest to breed. You may also encounter diverse mushrooms, but you should keep in mind that mushroom picking and foraging for plants and flowers is forbidden. The Sonian Forest is a UNESCO World Heritage site, meaning that even the tiniest elements of nature are crucial for the preservation of its ecosystem.