May be of Hellenistic origin when cistern system went out of use.
For a general note on the cistern see Nb. ΟΕ III, pp. 246 ff.
Objects from B 586 various depths (no subdivision): S 2324-S 2330,
P 34894, ... Late 2nd-early 6th c. A.D.
Well (stone-curbed shaft) near middle of Tholos which served the prior building.
Period of Use dated to ca. 500-480(?) B.C., Upper fill dated to ca. 480-470 B.C. or soon after in Agora XXX (a gradual ... Ca. 500-480 B.C.