Colmont Castle, Protected medieval fortress in Tongeren, Belgium

Colmont Castle is a medieval fortress in Tongeren featuring a ten-sided donjon with walls approximately 3.25 meters thick and an entrance on the second floor. The ruins sit on an artificially raised ridge surrounded by multiple moats that were once connected to the Herck river system.

The castle was built in the late 12th century by Gerard II of Loon and served as a defensive stronghold between the Landgraviate of Brabant and the Principality of Liege. Its strategic position made it an important military post in this contested region.

The name Colmont survives in the hamlet and in the nearby Oude Kolmontstraat, where the ruin stands. A document of 1175 mentions a castellan of Colmont, Elbertus, the first written trace of the site; local legend instead traces it to Roman times. The ten-sided donjon is the best-preserved element, with each face 4.7 m wide and walls 3.25 m thick pierced by holes that probably held the wall-walk.

The ruins are accessible on foot across the artificial ridges and old moats, with the elevated location offering good views of the surrounding area. It helps to wear comfortable walking shoes and be careful on uneven ground.

The stronghold contained an oval tower for garrison quarters and a square residential tower spanning three levels, connected by various auxiliary buildings. This unusual combination of different tower shapes was uncommon in medieval fortifications.