Here is the moment the whole trip was built for. You are sleeping ten minutes from the entrance, so you can be at the gate for the earliest slot, walk up through the Propylaia while the marble is still cool, and stand on the plateau with the Parthenon filling your view before the coach convoys and the midday glare arrive — which is precisely the must-avoid this itinerary has been shaped around. April mornings are crisp and clear, the light comes in low from the east, and the Pentelic marble shifts from grey to honey in about twenty minutes.
The history is almost too much to hold at once. The Parthenon was raised between 447 and 432 BC under Pericles, designed by Iktinos and Kallikrates with Phidias overseeing the sculpture, and it is the most sophisticated building of the ancient world — full of optical refinements: columns that swell very slightly in the middle, a platform that curves upward, corners sharper than they look. None of it is visible; all of it is felt. Inside once stood Phidias' twelve-metre Athena Parthenos in gold and ivory, long since vanished. Beside you the Erechtheion holds the Caryatids, the six maidens carrying its porch, and the spot where Athena's sacred olive and Poseidon's salt spring competed for the city's patronage. The building has had more lives than most cities: temple, church, Latin cathedral, mosque, and finally a powder magazine, which is why a shell fired by Morosini's Venetians in 1687 blew out its centre. When the Persians burned the Acropolis in 480 BC, Athenians buried the shattered statues as fill — which is why the museum below holds such an extraordinary collection of archaic korai, some with their paint still intact.
Do not rush the plateau, but do not linger past the cool hours either. Walk the north edge for the city view, find the olive tree, and save the close looking for the museum — by the time the first big groups crest the steps, you will already have had the site almost to yourselves.
Notes
Shoes with real grip: the marble is polished glass in places and unforgiving when damp. There are water fountains near the entrance, so fill your bottle. Bags and umbrellas go through a search at the gate, and if the west queue looks heavy, ask your hotel whether the south-slope gate by the Theatre of Dionysos is open that day. Buy whichever ticket version suits you and keep it if you have the multi-site one, because the Ancient Agora is next.