To the south of the Bouleuterion is the Southern Stoa, built in the 4th century BC. It had a Doric external colonnade and an Ionic internal colonnade. It may have served as an official entrance into the sanctuary.

To the east of the Bouleuterion is the Triumphal Arch of Nero, built in 60 AD. In Roman times, the procession to the Olympic games passed through its arch.

The Southern Stoa Roman Arch Foundation