The two towers, built between 1470 and 1485, the upper parts of which are arranged in terraces, are attributed to Jan Van Ruysbroeck, the court architect of Philip the Good, who also designed the tower of Brussels' Town Hall and the Collegiate Church of St. Peter and St. Guido in Anderlecht. They are unfinished and were meant to be much higher, in a style close to the Town Hall's tower or the north tower of the Cathedral of Our Lady in Antwerp.