Villa d’Este dazzles with artificial glamour, but the Villa Gregoriana relies more on nature. The gardens were built by Pope Gregory XVI in the 1830s and reopened in 2005 after a $5.5-million restoration. The main highlight is the panoramic waterfall of Aniene, with the trek to the bottom on the banks of the Aniene river studded with grottoes and balconies that open onto the chasm. The only problem is that if you do make the full descent, you might need a helicopter to pull you up again (the climb back up is fierce). From one of the belvederes, there’s a view of the Temple of Vesta on the hill. A former school has been converted into a visitor center designed by architect Gae Aulenti.