1. The Ravenna mosaics, most of all at St. Vitale.
2. Monreale, the Norman church outside of Palermo, Sicily.
3. Matthias Grünewald’s Isenheim altar, in Colmar, France.
4. Tiepolo’s paintings in the Residenz, in Wurzburg.
I much prefer any of those to the Mona Lisa, and to my prejudiced taste they are all among the very greatest of artistic masterpieces. They are all worthy of pilgrimages.