Collégiale Ste-Gertrude

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This 11th-century church was part of one of Europe’s foremost abbeys, founded in 648. It's 102m long with a soaring multilevel western facade topped with a squat octagonal tower flanked by turrets. The interior’s enormous Romanesque arches are unadorned, but notice the 15th-century chariot that’s still used to carry Ste-Gertrude’s silver châsse during Nivelles’ principal procession. Fascinating and detailed 90-minute guided tours in French get you access to the crypt, the tower gallery and the pretty cloister for photogenic views.

The pleasant cloisters are another highlight. Outside, watch the southern turret to see a 350kg gilt statue strike the hour with a hefty hammer. Tours also take in archaeological excavations and the grave of Charlemagne’s lofty first wife, Himeltrude, whose 1.85m skeleton can be seen reflected by a well-placed mirror.

The abbey's first abbess, Gertrude, was a great-great aunt of Charlemagne's, and was later sainted for her miraculous abilities, including rat catching (which warded off plague) and devil snaring (which saved the mythical Knight of Masseik from losing a Faustian bargain).