Editing Eleusinion (section)

===Outer propylon===
A propylon (gateway) was built into the peribolos wall on the west side, near the southern end, in the 2nd century BC, opening onto the Panathenaic Way. It served as the main entrance to the Eleusinion thereafter.{{sfn|Miles|1998|pp=71-72}} It was a porch, with an H-shaped ground plan, i.e. two walls perpendicular to the peribolos wall which supported a roof, and a cross-wall between them, containing the actual doors.{{sfn|Miles|1998|pp=73-74}}

The foundations are consist of poros, conglomerate, and marble blocks - many of them reused - set directly into the bedrock.{{sfn|Miles|1998|p=72}} In the centre, the foundations were covered over by [[Hymettos|Hymettan marble]] pavers, some of which survive. The date of construction is indicated by pottery sherds found in the packing of the foundations and by parallels with other Athenian structures of similar date.{{sfn|Miles|1998|pp=74-75}} It precedes cuttings made into the bedrock to the west in order to lower and pave the Panathenaic Way in the first and second centuries AD.{{sfn|Miles|1998|p=75}}

The propylon was incorporated into the Post-Herulian Wall in the late third century AD.{{sfn|Miles|1998|p=72}}