Walzin Castle, Medieval castle in Dréhance, Belgium

Walzin Castle is a Gothic Revival castle on a sheer rock above the right bank of the Lesse, about 5 km before its confluence with the Meuse. Its continuous range of light grey masonry walls and steep dark grey conical and pyramidal roofs ends in round towers at both sides. The 15th-century Renaissance horseshoe tower with four cannon ports still stands.

The fortress originated in the 11th century as a military stronghold commanding a river crossing. Successive renovations in the 1800s and early 1900s transformed its appearance into the current form.

The castle stands at a former ford of the Lesse, the only southern approach to Dinant, and was long a watch post for the town. Today the wooded Bois du Chaleux surrounds it, and kayakers on the Lesse see the castle from the water. The gardens were laid out by Louis Julien Breydel, also responsible for the Botanical Garden in Brussels.

The castle is private property and cannot be visited inside, and the gardens are not open to the public either. The building can be seen from the Lesse valley, for example from the popular kayak routes on the river. A guided walk is held every Thursday at 10 am during the summer.

The 11th-century keep survives from a hill castle that was razed four times; its ruined wall remnant is about 13 metres long and between 1.70 and 3.30 metres thick. The 15th-century Renaissance horseshoe tower with four cannon ports also still stands, though the French army burned the castle in 1554.