9Basilica of Saint-Pierre-aux-Nonnains
Next on our top list is the Basilica of Saint-Pierre-aux-Nonnains, the oldest one still standing in France.
Built in Metz, initially as a Roman gymnasium for a spa complex, in 380 AD, the structure was converted into a church in the 7th century, becoming the chapel of a Benedictine nunnery.
In the 16th century until the 1970s, the building became a warehouse, and later it was restored and opened for exhibitions and concerts.
