Most of Arezzo was destroyed by WWII bombing but parts of the mediaeval centre have remained intact. The biggest reason for coming is of course the incredible frescoes by Piero Della Francesca in the Chiesa San Francesco. The frescoes took 12 years to complete and is widely regarded as one of the greatest Italian works of art. Access is limited to 25 people every half hour so to avoid disappointment you can book ahead with www.pierodellafrancesca.it and have the benefit of an audio guide explaining the Legend of the True Cross.