Large building measuring 111 x 98 m., comprising a spacious rectangular courtyard surrounded by stoas, shops and storerooms. It has an east, Ionic propylon and a west, Doric propylon, known as the Gate of Athena Archegetis.
The most important monuments of the site are:
- Gate of Athena Archegetis. It stands on the west side of the Roman Agora. The monumental entrance has a row of four Doric columns and a socle made of Pentelic marble. It was constructed in 11 B.C. with the donations of Julius Caesar and Augustus and was dedicated by the People (Demos) of Athens to their patroness, Athena Archegetis.
- East Propylon. The east entrance to the Roman Agora had a row of four Ionic columns made of gray Hymettian marble. It was built in 19-11 B.C.
- Fethiye Djami. The Turkish mosque lies on the north side of the Roman Agora. It was constructed in 1456 A.D. on the ruins of an Early Christian basilica.
- Agoranomion. Rectangular building to the east of the Roman Agora, dated to the 1st century A.D. It preserves the facade which had three doorways with arched lintels and a broad stairway. An inscription on the architrave mentions that the building was dedicated to the Divi Augusti and Athena Archegetis. It might be identified with the Sevasteion, that is, a building for the worship of the emperor.
- The public latrines (Vespasianae) were housed in a rectangular building and consisted of an antechamber and a square hall with benches bearing holes on all its four sides, and a sewing pipe underneath. Dated to the 1st century A.D.