Sonian Forest

The Sonian Forest covers about forty-four square kilometres on the southern edge of Brussels and is what survives of the great Charcoal Forest that once ran across this part of Europe. Its character comes from the eighteenth century, when the Austrian administration replanted it with beech in regular stands, producing the tall straight columns of trunk that give it the name the beech cathedral, with a high canopy and almost no undergrowth. A core area of old-growth beech was added in 2017 to the UNESCO listing of ancient and primeval beech forests across Europe. Roe deer, wild boar and a large bat population live in it, and it is threaded with paths, cycle routes and bridle ways, with an arboretum, an abbey ruin and a wildlife bridge over the ring road.

History

The forest is one of the scattered remains of the ancient Silva Carbonaria, the Charcoal Forest, and is first recorded in the early Middle Ages as the Soniaca Silva; for a long time it served as an exclusive hunting ground for the nobility. At the start of the 19th century it was still more than twice its present size, but Napoleon ordered 22,000 oaks to be cut down to build the Boulogne flotilla for the invasion of England, and under King William I of the Netherlands it shrank from about 120 square kilometres in 1820 to 45 in 1830; in 1815 rights to a large part near Waterloo were assigned to the Duke of Wellington, and in 1861 the Bois de la Cambre was formed out of it. In the 20th century roads and motorways, among them the Brussels Ring, were cut through the forest, and in 2017 parts of it were inscribed as a World Heritage Site (Wikipedia, Sonian Forest).

What you'll find

• The beech cathedral - tall straight trunks and a high closed canopy.
• Old-growth core - the section added to the UNESCO beech forest listing.
• Roe deer and boar - the resident large mammals of the forest.
• The Groenendaal arboretum - a collection of exotic trees within the forest.

When to go

April to October, with May for beech leaf and October for colour. Half a day. It is used heavily by Brussels at weekends; weekday mornings are quiet. Paths are muddy in winter.

Good to know

Motorways and the ring road cut the forest into sections and traffic noise carries. Paths flood in winter. Boar are present and can be aggressive around young. It is very busy at weekends near the accessible edges.

Nearby

Tervuren and the Africa Museum are east; central Brussels lies north.

Key facts