The Eglise Saint-Sulpice is undoubtedly one of the most beautiful in Paris, and the second largest church in the city after Notre-Dame-de-Paris. It's well worth an extended detour!
The beautiful church of Saint-Germain-des-Prés has been through destruction and reconstruction. Fortunately, it's still standing today. And it's one of the last vestiges of Romanesque art in Paris!
