Hallerbos

For most of the year the Hallerbos is a pleasant, well-kept beech wood on the edge of the Brussels commuter belt. For two or three weeks between late April and mid-May it becomes something else entirely: wild bluebells open across the forest floor before the beech canopy has fully closed, and the ground under the smooth grey trunks turns a continuous violet-blue that runs up the slopes and into the hollows as far as the eye can follow. The effect depends on timing and light – the leaves overhead are still a thin, bright green, so the whole wood seems lit from below by the flowers.

The forest covers about 552 hectares south-east of the town of Halle, most of it in Flanders and a small part across the language border in Wallonia. It is a fragment of the Silva Carbonaria, the great "charcoal forest" that once stretched across this part of the Low Countries, and it is first mentioned in 686, when Saint Waltrude's estate here passed to the abbey chapter she had founded at Mons. Later it belonged in part to the Dukes of Arenberg; in 1779 the two owners had the wood surveyed and divided, marking the line with pyramid-shaped boundary stones carved SW on one face and AR on the other. Nineteen of them still stand along the old dividing line – small, easily missed witnesses worth looking for among the trees.

The beeches themselves are younger than the forest's reputation suggests. During the First World War the occupying army felled almost every large tree, and after the land passed to the Belgian state the wood was replanted between 1930 and 1950. What survived was the ground: a plateau around 120 metres high cut by five small north–south valleys with springs in their floors, and old tracks worn down into deep sunken lanes. That varied relief, together with patches of oak, ash, pine and larch planted to suit the soils, keeps the forest from feeling uniform. Wood anemones and wild garlic are among the other spring flowers, and roe deer, woodcock and nightjar are among the resident species. Since 2021 the Hallerbos has been a Flemish nature reserve, and it is protected under Natura 2000 and part of the Brabantse Wouden National Park.

Getting there

The forest lies just south-east of Halle, about 6.5 km from Beersel, and roughly 25 km from Brussels Airport (BRU). From Halle railway station regional buses run towards the edge of the forest. Waymarked walking routes start from the forest entrances. The bluebells peak for only a short time, usually from late April to mid-May.