Well under Poros Building Drain at 62/ΛΣΤ, west of the Areopagus. Digging abandoned at 6.10m due to a collapse of the soft bedrock at the west. Small amount of supplementary filling was added in the upper ... Ca. 520-480 B.C ... Well under Poros Building Drain at 62/ΛΣΤ, west of the Areopagus. ... Small amount of supplementary filling was added in the upper part of the well, probably when the cutting was bridged over to allow for the building of the Poros Drain.