The Odeon from the 1st century B.C. and renewed in the 2nd century A.D. is directly connected to the portico of the lower agora. The walls were covered with marble panels. The orchestra was covered with square slabs.

It is said that the Odeon was used as a bouleuterion during the reign of Emperor Hadrian.
On the outside there was a cassette frieze above the 3 doors. In the middle of the frieze was a life-size portrait of Emperor Hadrian. To the left and right of it, the frieze showed masks and representations of various gods.
In addition to the three doors leading from the portico into the Odeon, two other entrance doors were recessed into the corners of the back wall. The left door was connected to the portico by a staircase, while the right door was connected to the stairway to the upper agora.