is so named NOT because Caesar supposedly stationed troops there, but because Emperor Charles V (Kaiser-Caesar) was a frequent visitor to this former Dukes’ of Brabant castle that used to overlook Leuven from this mount. Holy Roman Emperor and Hapsburg monarch, Joseph II (eldest son of Maria Theresa) had the castle torn down, and its stones used to shore up the hillside.Today, Keizerberg is known for its Benedictine Abbey which sits on the site of the former castle.