Marvel at the size of Cathedral of Saint Catherine. Schedule in a service if you can or simply take a seat and appreciate the peace and quiet.
You're spoiled for sightseeing choice when staying in Utrecht City Center. Cathedral of Saint Catherine is an ideal place to kick off here, but there are loads of other interesting spots to check out. Hoog Catharijne, Beatrix Theater, and TivoliVredenburg are near the principal church and will fill in your day nicely.