Basilica of Saint-Pierre-aux-Nonnains

The Basilica of Saint-Pierre-aux-Nonnains in Metz, France, is one of the oldest churches in Europe. Originally built in the 4th century AD as part of a Roman thermae (public baths) complex when Metz, then called Divodurum, was a major Gallo-Roman military and trade centre. In the 7th century, the structure was converted into a church serving a Benedictine nunnery. Charlemagne favoured the old church, and two of his sons were buried there. The Roman walls remained largely intact through the Middle Ages, but by the 16th century the building was repurposed as a warehouse for over 400 years. Recognized for its historical importance in the 1970s, it was restored and now serves as a concert hall.