Kasteel van Horst, Renaissance castle in Sint-Pieters-Rode, Belgium.

Kasteel van Horst stands in Sint-Pieters-Rode, Holsbeek, in a large pond that doubles as its moat. The walls show alternating light and dark horizontal bands, their greenish tint coming from glauconite, a clayey building stone. A square donjon with a steep pointed roof and small spire rises on the right, its upper section resting on corbels; a round turret with a conical roof marks the far left corner. The main block has a slate-grey hipped roof with dormer windows and chimneys, and regular rows of windows, including large cruciform windows on the moat side.

A "Rode Castellum" is cited in 1100, and by 1263 the castle belonged to Jean de Horst; in 1292 Jean de Lantwyck married Marguerite de Tervueren, natural daughter of Duke Jean I of Brabant. Amelric Pynnock, who bought the lordship in 1369, converted the fortified farm into a water castle. It was destroyed during the 1488-1489 revolt against Maximilian of Austria, rebuilt by Lodewijk III Pynnock, and ceded to Ivan van Cortenbach in August 1500.

The castle is home to the comic character De Rode Ridder (The Red Knight) by Willy Vandersteen, and it has served several times as a television filming location, for series such as Buiten De Zone and Thuis. Each year the grounds host Kasteelfeesten, castle festivities at which staged knight tournaments are performed.

Reaching the castle requires taking a train from Brussels or Leuven to Aarschot, then boarding bus number 10 to the location. Check opening hours ahead of time and prepare for a longer journey to get there.

The castle is the home base of the comic character De Rode Ridder (The Red Knight) created by Willy Vandersteen, and it has served several times as a television filming location, for series such as Buiten De Zone and Thuis. In 2007 Countess de Hemricourt de Grunne sold the estate with its 113 hectares of surrounding land to the Flemish Region.