The South Stoa, one of the largest porticoed buildings in ancient Greece, was built in the late 4th century B.C., to the south of the race track of Corinth. The excavation of it by the American School of Classical Studies was begun in 1933 and completed in 1948.
The Stoa covers an area of about 0.4 hectares and measures 164.38 meters x 25.15 meters. Its facade has 71 Doric columns, and it had a second internal colonnade of 34 Ionic columns. The back part of the Stoa consisted of 33 similar two-roomed apartments. The ground-floor rooms were equipped with wells to keep water and wine cool and served as shops and restaurants. Of these apartments in the Hellenistic Stoa, the three at the west are in a good state of preservation.
During the Roman period (1st-3rd centuries A.D.), the majority of the rooms in the Stoa were converted into separate areas of differing sizes and uses. Of these, we may single out: the Agonotheteion, which was connected with the Isthmian games, a propylon, which lead to the South Basilica, a fountain House, the Bouleuterion, which dates from the second half of the 1st century A.D., a Late Roman bath and public latrine dating from Late Antiquity.
About the middle of the 1st century A.D., a paved road leading to Kenchreai ran through the middle of the Stoa. Although the back part of the Stoa gradually lost its fine appearance and unified function, the front part, with the two colonnades, retained its form and unity.
The Stoa was finally abandoned in the 6th century A.D.