Built in the old trade center of Ghent next to the bustling Korenmarkt (Wheat Market), St. Nicholas' Church was popular with the guilds whose members carried out their business nearby. The guilds had their own chapels which were added to the sides of the church in the 14th and 15th centuries.
The central tower, which was funded in part by the city, served as an observation post and carried the town bells until the neighboring belfry of Ghent was built. These two towers, along with the Saint Bavo Cathedral, still define the famous medieval skyline of the city center. One of the treasures of the church is its organ, produced by the famous French organ builder Aristide Cavaillé-Coll." (Text from Wikipedia).