With 3,000 years of history, you can’t turn around in Athens without encountering the past. The Acropolis, a UNESCO site, the Plaka, and the Acropolis Museum are must-sees. But leave time if you can to climb Pnyx Hill for photos of the Parthenon at sunset, to buy your own set of Greek komboloi (worry beads), and to explore the metro stations that serve as mini-museums for the relics that are constantly being unearthed.