The Belfort (Belfry) was built in the 13th and 14th centuries with stone from Doornik.

Guards on the towers used to tour the battlements on the hour in order to demonstrate that they were not asleep. Their tasks included
keeping a look-out for a possible enemy, to raise the alarm in the event of fire, and to ring the bells during times of great danger.

In the "Het Secreet", the lowest room in the Belfort, the precious charters and documents granting priviledges were once kept.

Within the tower is the Beiaard, consisting of 44 bells - one of the best known carillons in the Low Countries. The present day spire was only completed in 1913.