The original Agora was encroached upon and obstructed by a series of Roman buildings, beginning with the imperial family’s gift to the Athenians of a large odeion (concert hall). The Odeon of Agrippa was built by him in around 15 BC, and measured 51.4 by 43.2 metres, rose several stories in height, and – being sited just north of the Middle Stoa – obstructed the old agora. In return for the odeion, the Athenians built a statue to Agrippa at the site of the previous agora; they based it on a plinth recycled from an earlier statue by covering the old inscription with a new one.

North of the odeion was a new temple to Ares, which completed the repurposing of the old agora. The functions of the old agora were transferred to the Roman Agora, which was built around 100 metres east of the original agora. The Roman Agora has not today been fully excavated, but is known to have been a peristyle open space. To its south was a fountain. To its east, behind a marble colonnade, were shops and an Ionic propylaeum (entrance). To its west was a Doric propylaeum. Source: Wikipedia