Saint-Sulpice is one of the great Left Bank churches, a vast classical building just north of the Luxembourg Gardens. Its mismatched towers and broad façade make it easy to recognise, while the interior is known for Delacroix murals, a grand organ, and the old astronomical gnomon.
It is a strong stop in Saint-Germain-des-Prés because it feels both monumental and local. The square outside is also a good place to pause between the Luxembourg Gardens and the streets around Odéon.