Castle of Westerlo, Medieval castle in Westerlo, Belgium

The Castle of Westerlo, locally called Oud Kasteel, is a brick castle rising from the water, with a tall central block under a slate roof topped by an octagonal cupola. Round brick turrets with conical roofs flank the front corners, and a stone band runs below the roofline. The central keep has walls over 2 m thick, built in local brown stone in the late 14th century.

The lords of Wesemael built the central keep in local brown stone in the late 14th century, probably replacing an earlier fortress. In 1484 the castle passed to the de Merode family, who still live there; from the 16th century it lost its fortified character, and 19th-century restorations gave it a medieval look again.

The rooms display tapestries and family portraits that show the lives of the nobility who lived here over centuries. Visitors can observe how European art collections and personal objects shaped the character of each space.

The building is open to visitors on certain summer days and offers guided tours through selected rooms. Visitors should wear sturdy shoes, as paths through the park can be uneven.

The grounds contain two distinct building complexes: a medieval structure and an addition from the early 20th century. These two structures reveal how the family adapted and enlarged their home across generations.