This old fortified castle, remodelled in 1536 to the designs of Vincidor of Boulogne's, this castle was a favourite retreat of William the taciturn. It was given its current look between 1686 and 1695 under the stathouder William III of Orange to the designs of Vincidor. It is an enormous moat-castle with many windows, which stands out against the walls of the Het Spanjaardsgat. It's northern facade is flanked by octagonal turrets.