The Telesterion, or the Temple of Demeter, is at least six layers deep, each layer successively larger than the preceding layer below. The oldest layer dates to Mycenean times. The ruins of the structure now seen are the remains of the Periclean rebuilding as remodeled by Marcus Aurelius. Eight tiers of seats, half hewn from the rock, half built upon it, completely covered in marble during Roman times, line all four sides of the temple, allowing for over three thousand spectators. The seats are broken by six entrance ways, two each on the north, east, and south sides. In the center was the Anaktoron, forbidden to all but the Hierophant. It was from the inner sanctum that the Hierophant would reveal the Hiera. The south-eastern front of the Telesterion is adorned by the portico of Philo, or the Stoa of Philon. A well cut into the rock beneath may be the original Kallichoron. To the east, steps lead up to a terrace and to a possible treasury.

Telesterion from south west "Old Telesterion" The Anaktoron

Seats in Telesterion Stoa of Philon