Athens is best explored on foot, with time to take a wrong turn or stop for a coffee along the way. Start your day by visiting the Acropolis, then wander downhill into Plaka, where shaded lanes open onto little squares and tavernas set out their tables. The Acropolis Museum is worth stopping by before the afternoon heat sends you on the lookout for a cool drink. Later, join the crowds around Monastiraki, browse the market streets and head up Mount Lycabettus as the sun sets over the rooftops.
With White Trails, you can add a half-day excursion from Athens to Cape Sounion, where the Temple of Poseidon overlooks the Aegean.