|Summary:||Large, almost square building; on west side of the Agora, north of the Prytanikon.|
|Date:||ca. 500 BC|
23.8 m x 23.3 m.
Divided into a north seating area and a south lobby by a partition wall. Seats lined 3 sides of the east section, probably there were 5 internal supports for the roof. At the southwest corner the structure shared a gated wall connected to the Prytanikon.
Originally built to house the Council of 500 (introduced by Kleisthenes), this served as the state archives after the New Bouleuterion was built ca. 415 B.C. The reconstruction of the seating differs. In Travlos the Old Bouleuterion seating is reconstructed without aisles and the partition wall and outside south wall have doors. Camp uses Dinsmoor's drawing of 1984 which reconstructs the seating with aisles, and shows the partition and outside south wall as partially columned. The plan accompanying this card is based on Camp's reconstruction.