Imagine a cathedral built entirely of beech trunks, grey and smooth, rising forty metres or more to a roof of leaves, and you have the Sonian Forest at its finest. This great wood on the south-eastern edge of Brussels, the Forêt de Soignes or Zoniënwoud, covers thousands of hectares, and its most remarkable stands, including the Grippensdelle reserve near Hoeilaart, are part of the transnational World Heritage Site of the Ancient and Primeval Beech Forests of Europe, inscribed in 2017.
The famous cathedral of beeches is not entirely natural. Much of it was planted in the late eighteenth century, when the Austrian Habsburgs ruled the Southern Netherlands and a landscape architect named Joachim Zinner replanted large parts of the forest with beech in tight rows. Those trees are now huge and old, and in the protected reserves the forest is being allowed to age and decay naturally, with fallen trunks left to rot and feed beetles, fungi and woodpeckers. The ground is rolling, with little valleys and ponds, and in spring a carpet of bluebells and wood anemones covers the floor before the canopy closes.
Hoeilaart, three kilometres away, has a curious claim to fame: for more than a century it grew table grapes in heated glasshouses, and the village still celebrates its grape festival. The remains of the glasshouses can be seen on the hillsides, and the local grapes were once exported far and wide. La Hulpe, to the south, has a large park and château that belonged to the Solvay family.
The roads through the forest are pleasant but busy. Several main routes cross it, carrying commuters into Brussels, and the Brussels ring road runs along its edge. Speed limits are low and cyclists are many. The smaller lanes around Hoeilaart, Overijse and Tervuren are quieter and more enjoyable, with short climbs and descents through woods and villages. The forest itself is best explored on foot; numerous car parks give access to the trails.
Hoeilaart has fuel and shops, and the nearby towns of Overijse and Tervuren have restaurants and cafés. Tervuren is also home to the AfricaMuseum, which has rethought its colonial collections in recent years. Walking among the beeches on a misty autumn morning, with the leaves turning copper and the city a world away, is one of the great pleasures of the Brussels area.