Long before philosophy arrived, the site was holy ground. It held a grove of olive trees dedicated to Athena, goddess of wisdom, and a cult that reached back to the Bronze Age. Its archaic name was Hekademia, later softened to Akademia and linked by tradition to the hero Akademos, who was said to have revealed to Castor and Polydeuces where Theseus had hidden Helen. Out of respect for that legend, even the invading Spartans spared these "groves of Academe." The Roman general Sulla showed no such reverence: in 86 BC, besieging Athens, he cut down Athena's ancient olive trees to build siege engines. The Athenian statesman Cimon had earlier enclosed the precinct with a wall and laid out shaded walkways, turning a wild grove into a place fit for gathering.

Plato's Academy looked nothing like a lecture hall. It was an exclusive club that charged no fees, with senior and junior members rather than teachers and pupils in any rigid sense. Rather than handing down doctrine, Plato posed problems for the group to wrestle with, favoring the back-and-forth of dialectic over the monologue of the lecture, though he is recorded to have delivered at least one famous talk, "On the Good." The subjects ranged remarkably wide for the age: mathematics, astronomy, and the great questions of ethics and politics that fill the Platonic dialogues. Two women are known to have studied here, Axiothea of Phlius and Lasthenia of Mantinea, at a time when Athenian public life largely excluded women. A later story, written centuries afterward, claims the words "Let None But Geometers Enter Here" were inscribed above the door.

The Academy's most famous student arrived as a teenager and stayed for twenty years. Aristotle studied under Plato from 367 to 347 BC before founding his own rival school, the Lyceum, and going on to tutor Alexander the Great. After Plato's death, a succession of leaders called scholarchs guided the institution: Speusippus, then Xenocrates, then Polemo. Under Arcesilaus in the third century BC the Academy took a sharp turn toward skepticism, doubting whether certain knowledge was possible at all, a stance the school largely held until the time of Philo of Larissa, often called its last undisputed head. The original Academy did not survive Sulla's siege, and Philo's flight to Rome effectively closed the book on the school's continuous life.

The name proved more durable than the place. Around AD 410, Neoplatonist philosophers revived an "Academy" in Athens, presenting themselves as Plato's heirs across an eight-hundred-year gap, though no real institutional thread connected them to the original. This later school flourished under the brilliant Proclus, who died in 485, before Emperor Justinian placed it under state control in AD 529, an act usually remembered as the closing of the Academy and a symbolic end to classical pagan learning. The physical site, near ancient Colonus about 1.5 km north of the Dipylon gates, was lost for centuries and rediscovered only in the twentieth, in the modern Akadimia Platonos neighborhood. Excavated and free to visit, it is a humble archaeological park, but its true monument is every school on Earth that calls itself an academy.