The theatre at Epidaurus was built into a hillside on the Peloponnese, part of a sanctuary dedicated to Asclepius, the god of healing. Its acoustics became the stuff of legend: visitors are told they can hear a coin drop or a match struck from the back row. Modern researchers are more careful, but they have found something real. The limestone of the seats acts as a natural filter, dampening the low-frequency murmur of a crowd while letting a human voice rise intact. The ancients did not have the physics, but they had the ears. Sit in the top row at dusk, watch the actors below grow small as figures on a coin, and hear every syllable arrive whole. The building was designed to do exactly this, and after two millennia it still does.

What the festival stages is not a museum reconstruction but the living repertoire of ancient Greek drama. The tragedies of Aeschylus, Sophocles, and Euripides; the comedies of Aristophanes, biting and bawdy as the day they were written. These are the founding texts of Western theatre, and at Epidaurus they are performed on the ground where the form took shape. For its first twenty years the festival belonged largely to the National Theatre of Greece and to actors whose names became synonymous with classical performance: Paxinou, Minotis, Anna Synodinou. In 1959, Karolos Koun's staging of Aristophanes' Birds, with music by Manos Hadjidakis, so provoked the authorities that the government forced it to close. Ancient comedy, it turned out, could still draw blood.

The festival has a second home in the capital, beneath the Acropolis. There, on the marble of the Odeon of Herodes Atticus, a Roman theatre from the second century, the program turns to music and dance alongside drama. The list of who has performed there reads like a century of the performing arts compressed into one venue. Maria Callas sang Bellini's Norma at Epidaurus in 1960 — the first opera ever performed in that ancient space. Herbert von Karajan conducted the Berlin Philharmonic in 1962. Rudolf Nureyev and Margot Fonteyn danced; Luciano Pavarotti and Montserrat Caballe gave recitals; the New York Philharmonic came under Leonard Bernstein, then Zubin Mehta. In 1982, Peter Hall brought Aeschylus' Oresteia to Epidaurus — the first non-Greek-language production ever performed in that ancient space.

The festival has not floated above its country's history. During the years of the military junta, from 1967 to 1974, the program stagnated and turned inward, the open-air theatres a quieter place. Recovery came slowly. In 1980, Spyros Evangelatos brought his Amphi-Theatre company to Epidaurus with Menander; the Theatrical Organization of Cyprus arrived the same season. Today the joint festival runs from May into October under the artistic direction of a rotating cast of Greek theatre figures. The premise has never changed. Take the oldest drama in the European tradition, set it under a summer sky in the place it was made for, and let a new audience discover that these ancient voices were never really silent.