Many of the streets in the walled city of Ferrara are lined with elegant palaces. Unfortunately, what are perhaps the most beautiful parts of the city, the courtyards and gardens hidden within, aren't accessible for the most part. In the center of town, you can explore a few rooms in the striking Castello Estense, once the home of the Este dynasty, which ruled the city from the 13th to the 16th century. The castle's moat is intact, water and all, which is somewhat unusual. You can also visit its prison, where in 1425, Duke Nicolo d'Este had his young second wife and his son beheaded because he found out they were lovers (the story inspired the Browning poem "My Last Duchess"). Nearby is the Duomo, which has a gorgeous and very intricate facade. Our favorite of Ferrara's several museums is the Pinacoteca Nazionale (with paintings by the Ferrara School of artists). It's housed in the Palazzo dei Diamanti (Palace of Diamonds), which gets its name from the 12,500 pieces of diamond-shaped marble that make up its facade. Make sure to do as the locals do and take a walk on the ramparts surrounding the city -- there are walking paths and even parks with trees up there.