"The Gothic-style Basilica di San Francesco, considered the most beautiful church in Arezzo, was reworked in the 1300s to become what it still is today. The wealthy Bacci family, whose story you can learn about on a guided tour, kickstarted the church's magnificent series of interior frescoes, which are still in near-perfect order. (There's also a large and arresting crucifix on the altar.) You can show up and have a peek, sure, but to truly see this monument you need to book timed tickets in advance." - Bridget Arsenault