Temple of Olympian Zeus

No building in Athens has a funnier construction history. The tyrant Peisistratos began the temple around 520 BC, sized to out-do everything in Greece; the tyranny fell, and democratic Athens pointedly left the megalomaniac's foundation empty for three and a half centuries. A Hellenistic king restarted it, Rome looted columns from it for the Capitol, and it took the emperor Hadrian — Athens' greatest fan — to finish it in 131 AD, six hundred and thirty-eight years after ground-break. The Athenians thanked him with a gold-and-ivory statue of Zeus inside and, characteristically, one of Hadrian right next to it.

What remains is scale you feel in your stomach: 15 columns of the original 104, Corinthian capitals like acanthus explosions, each shaft 17 metres of banded marble drums — nearly twice the Parthenon's height. The sixteenth column blew down whole in an 1852 storm and lies exactly where it fell, its drums fanned out like a sliced loaf: the single best illustration in Greece of how these buildings were actually assembled, and the detail everyone photographs once they notice it.

Hadrian's Arch stands free at the site's corner on the avenue, marking the line between the old town and the emperor's new quarter — its two inscriptions face each way: "This is Athens, the ancient city of Theseus" toward the Acropolis, "This is the city of Hadrian, and not of Theseus" toward the temple. Read both; the swagger has lasted nineteen centuries.

Twenty minutes covers the site, which is exactly its virtue: it slots between the Acropolis Museum and the National Garden with no planning, it's on the €30 combined ticket, and at golden hour the columns against Lycabettus Hill are one of the city's easiest great photographs. The fence view is free and decent — but the fallen column only reveals itself from inside.