Mantua. Another one of those Italian towns you’ve never heard of, right? Well, let’s start with the bedroom. A vast, dimly lit chamber with thick walls and bare tile floor, it is hardly cozy. More than 26 feet wide and roughly that tall, it is a chilly cube that nestles deep in the recesses of the Castello di San Giorgio.

But since 1475, when its frescoed walls shone fresh, the chamber has been acclaimed as one of the world’s most beautiful rooms. Even now its imposing portraits of the Gonzaga family, with their elegant courtiers, handsome horses and sleepy dogs, stand among Italy’s most famous art treasures.