Remarkably, there's not a single straight line in the entire building: Iktinos wrote the book on entasis (tension), subtly imitating the swellings and curves of nature, an almost subliminal visual trick that helps make the building so visually satisfying.Walking up the slope, you'll often find architects gazing dewy-eyed at the Propylaia, the ceremonial gate to the Acropolis, which many consider as sublime as the Parthenon. Built on extremely difficult ground, and incorporating, on one end, the bijou temple of Athena Nike, the structure still manages to be a model of classical grace and harmony. The third temple on the Acropolis, the Erechtheion (395BC) with its famous Caryatid porch, owes its unique layout to cult requirements – including the display of marks made by the trident of Poseidon and the olive tree invented by Athena, when the two gods contested to become patron of Athens.The Acropolis Museum houses several sections of the 524ft Parthenon frieze. Designed by the celebrated sculptor Phidias, the frieze, depicting the quadrennial Panathenaic procession, epitomises the classical spirit in the naturalistic yet idealised, godlike beauty of its figures.

The Greeks are building a state-of-the-art museum (due to be ready in 2004) near the Acropolis metro station, to hold the entire frieze in a single room overlooking the Parthenon, hoping to convince the British government to return the rest: the Elgin Marbles in the British Museum AND APRES ACROPOLIS? Sustenance and souvenirs, of course. The Plaka quarter, the heart of Athens before it became the modern Greek capital in 1834, is conveniently spread under the Acropolis, its narrow lanes packed with Roman ruins, Byzantine chapels, Ottoman mosques – and shops selling plastic glow-in-the-dark Parthenons as well as lively bars and tavernas. The oldest taverna, Platanos, at 4 Diogenis Street (00 30 210 322 0666), is still one of the best, with tables spread under an ancient plane tree. ANYTHING ELSE TO SEE OF CLASSICAL ATHENS? Plenty, and all in walking distance of Plaka. Scooped out of the Acropolis hill, the Theatre of Dionysos (00 30 210 322 4625, open daily 8am-7pm, 5pm in winter, €2/£1) is the oldest playhouse in the world, where drama as we know it was invented in the 5th century BC by Aeschylus, Sophocles and company, all competing for the prize in the annual festival in honour of the god of wine. Audiences were tougher back then – performances went on all day, and they had to sit on the ground, or perhaps on planks, until the theatre was rebuilt in stone in 342BC. Even then, one can't help thinking ancient bottoms must have been hard as nails.The heart of classical Athens, as in any Greek city, was the Agora (00 30 210 321 0185, open 8am-7pm, Oct-Apr until 5pm, €4/£3), the "marketplace" but also the civic centre, where every citizen went daily to meet, keep abreast of events, or get buttonholed by Socrates.

The Agora's Temple of Hephaistos (of Theseum) is the best-preserved classical temple in existence, complete with its coffered stone ceiling. Among their many accomplishments, the Greeks invented the modern shopping mall: the porticoed stoa, where one could shop or philosophise, sheltered from the sun or rain.These days the Agora's reconstructed Stoa of Attalus contains, instead of shops, a fascinating museum filled with art and everyday bits and bobs, from a classical era potty-training chair to a bizarre pachinko-like machine used to select jurors randomly.No place, however, better evokes classical Athens than Kerameikos, the ancient pottery district just north-west of the Agora, where all those beautiful Attic vases were turned and painted (00 30 210 346 3552, open 8am-7pm, €2/£1). This incorporates the majestic Dipylon Gate, through which the Sacred Way to Eleusis passed; along this road, for 1,500 years, Athens buried her dead. As you stroll Kerameikos's quiet lanes, lined with cypresses, dotted with its wistful, restrained funerary steles, and taking in magical views up to the Acropolis, it's easy to imagine that you're walking in the city of Plato and Aristotle.What you won't see of classical Athens, at least for now, are the contents of the blockbuster National Archaeology Museum, which is closed until late 2003 for an Olympic refurbishing. For more information, contact the National Tourist Organisation of Greece (EOT), 2 Amerikis Street (00 30 210 325 2895, ) THIS CLASSICAL STUFF CAN GET UNDER YOUR SKIN ... Even if you only have a long weekend in Athens, it's easy to take in some of the classical sites outside of the city.