The painted and terracotta coats of arms of its students, professors and priors. There are over 7,000 coats of arms which record the names and countries of origin of their bearers.
Those types of ceilings are so hard to figure out how to frame, shoot...whether to be symmetrical or not. I like how you did this one, angles on corners work to frame the ceiling view. I wonder if these date to 500 ad?