Castle Groenendaal, Medieval castle in Waltwilder, Belgium

Castle Groenendaal is an estate in Bilzen with U-shaped architecture, limestone friezes, and arched windows on its classical facades. An L-shaped service building from the early 1800s completes the complex with iron wall anchors for stability.

Croenendael was a fief of Looz held with Hoelbeek and Jonckholt; it was divided at the end of the 14th century and passed to Aleidis van Jonckholt, wife of Godenoel van Elderen. In 1477 it came to the Lamboy family. In 1757 Michel Joseph de Grady acquired it and around 1761 rebuilt the 17th-century Maasland Renaissance castle in classicist style; in 1861 it passed to Emile de Rosen de Borgharen.

The name Groenendaal is a later, factually incorrect replacement for the original Croenendael or Croonendael. The central salon carries late-18th-century stucco work with flower garlands, vases, turtle doves and baskets of fruit in Louis XV and Louis XVI styles. The castle itself is not open to visitors.

The estate is private property within a protected historical landscape, so visitors can view it from outside. The best time to see the facade details is during daylight hours when the stonework and carvings are clearly visible.

The current name is a corruption of Croenendael or Croonendael, the original name of this fief of Looz. The estate formed a single fief with Hoelbeek and Jonckholt until it was divided at the end of the 14th century, when it passed to Aleidis van Jonckholt, wife of Godenoel van Elderen.