Sainte-Trinité Basilica is the main historic church in central Cherbourg. It is not a grand cathedral stop, but it gives the old town a needed centre of gravity, with Gothic lines, later restorations, and a setting close to the streets around Place Napoléon.
Drop in while walking between the harbour and the Thomas Henry Museum. The church works best as part of that town-centre circuit, a reminder that Cherbourg is more than ferry ramps and naval walls.