Locals call it "Oud Kasteel" (Old Castle) () to discern it from the new castle built for Jeanne de Merode in 1910-12 (see below). The castle has been the home of the House of Merode for more than five centuries. The central keep or Donjon has walls of more than 2 m thick. I was built by the lords of Wesemael in local brown stone in the late 14th-century. It probably replaced an older fortress on the same spot. Other parts of the building are believed to date from the 15th and 16th century. The castle was adapted, extended and renovated several times. From the 16th century onwards it was transformed into a more luxurious noble dwelling and gradually lost its fortified character.