It’s a full-day excursion from Palermo to visit the Valley of the Temples at Agrigento, but the trip is well worth it. This UNESCO World Heritage Site has no fewer than eight Doric-style Greek temples that date back to the 5th century B.C.E. The Temple of Concordia is the most spectacularly intact, while the huge Temple of Olympian Zeus was one of the largest Greek temples in antiquity. Aqueducts, mosaics and Christian necropolises can also be seen at the archaeological site.