Domaine Solvay, Castle park in La Hulpe, Belgium.

Domaine Solvay is a 227-hectare public park in La Hulpe with woods, lawns and ponds. Its château, rebuilt in the 19th century and later restyled by architect Georges Collin, has a pale rendered facade, a steep slate roof with dormers and a slender finial. A 140-step stair leads to a belvedere, and an 800-metre grass avenue ends at a 36-metre obelisk topped with a gilded sun.

A nobleman acquired the land in 1833 and commissioned a castle built between then and 1842. The property gradually transformed into an organized estate with designed gardens and pathways.

The Folon Foundation has occupied the farm buildings designed by Jean-Pierre Cluysenaar since 1999, showing more than 300 works by Belgian artist Jean-Michel Folon. The farm, unused since 1971, was restored in 1982 at the expense of the French Community of Belgium; its barns first hosted exhibitions and concerts. A bistro called "l'homme bleu" occupies part of the farm.

The grounds are open daily year-round with free entry for all visitors. Multiple pathways of varying length allow people to walk at their own pace through different sections.

The 800-metre grassed axis cut through the forest in front of the château ends at a 36-metre obelisk topped with a gilded sun, built for Ernest-John Solvay. A staircase of 140 steps leads up to a belvedere he also had constructed.