Well west of the Eponymous Heroes monument. The shaft was of irregular width (ca. 0.81m where the full circle was first preserved), sunk in soft bedrock clay much of which had collapsed around the top ... Ca. 600-550 B.C ... Hesperia 37 (1968), p. 68 ... Agora XXI, p. 98 ... Agora XXIII, p. 333.
