multicolored dome building

This is a beautiful cathedral I uncovered while roaming around Italy. There is little-to-no information (in english) that I could find online. I was blown away by the 3-d sculptures that blended in with the painted realism images of different heavenly scenes. Incredible, artistic, and profound. I felt as if I was witnessing two dimensions, something hard to imagine yet so plainly demonstrated through two different art forms.