Possible Clues:

• City south of Paris with a distinctive Gothic cathedral
• French cathedral
• Cleaner, very French, where there's a Gothic cathedral
• Somewhere in France that's cleaner — and very French!
• Cathedral plans to include religious education
• Engineers opening plans for cathedral
• Cathedral maps, about to be introduced
• Famous French cathedral city
• French city with a cathedral renowned for its stained glass windows
• Orchestra, heading off to play in cathedral