In it's current shape this St-Gangulfus' church is a cross shaped church with a small built in west tower and a half round apse. This apse is accentuated on the outside via 3 rond arch windows deep windows.

Saint-Galgulfus' church is the eldest church in Saint-Truiden. The central aisle of this 3aisled church is romanesque, and dates from the 11th century. It is built in marl stone. You see the typic rounded arch windows and the heavy square pilars with rounded arches between the central aisle and the side aisles of the nave. The choir is 12th century.

Probably, there was an elder Carolingian predecesser church on this spot.

The 2 transepts (one transept being 1 church arm) are built in the 16th century in a typical gothic style, you can see that fe at the lancet windows. Side aisles and wooden ceiling are 18 century.

The triumph cross dates from the beginning of the 16th century.

In the tympanum of the main porch one sees a 13 till 14th century half-relief showing Christ on the Cross.

(Thanks to Lander Lismont, who sent us part of this text, translated by us)