"A sprawling palatial pavilion built by emperor Nero in the 1st century that will blow you away with the design taste and command of concrete and space on display. You can only visit on weekends—the site's under restoration during the week—but admission includes a guided tour. Ours was led by an archeologist who not only worked on the site but was totally obsessed with it; the passion made for a terrific tour. Try your luck." - Katie Parla, Maresa Manara