It is one of 56 belfries of Belgium and France that are inscribed on the UNESCO World Heritage List, in recognition of their civic architecture and importance in the rise of municipal power in Europe.

[1][2] The tower of the old church of Saint-Théodard, built without foundations on slate rock, is undeniably medieval and must date from the time of the greatest development of the city.

In the period between 1153 and 1164, during his visits to Thuin, the Prince-Bishop Henry II of Leez decided to erect a tower for the church.

The excavations undertaken on the site of the Chapter to the late twentieth century, reveal the existence of three successive religious buildings.

The tower was hit by German artillery August 24, 1914, and the damage was permanently repaired in 1952 by Michot carpenters, father and son.

With a total height of 60 metres (200 ft), the belfry is a square building Baroque style, with a tapered base on three levels with sandstone rubble and limestone harp angles.

On the bottom of the south face are sealed the arms of Peter the Tassier and Nicolas Brussels mayors in 1638–1639, during the work undertaken on the tourn.