Take in the grandeur of Modena Cathedral. Fit in a mass if you can or simply take a seat and enjoy a break from the outside world.
You'll be spoiled for sightseeing choice in Old Town Modena. Modena Cathedral is a great place to kick off here, but there are plenty of other worthwhile attractions to consider. Torre della Ghirlandina, Museo Enzo Ferrari, and Modena Autodrome are not far from the principal church and will round out your day nicely.