This is one of the most significant public buildings of the ancient city of Kos and is located south of the west archaeological site of the ancient theatre.
The Roman Odeon came to light after the excavations of Italian archaeologist L. Laurenzi in 1929. The first phase of restoration work was carried out by the Italian Archaeological Mission in the same year, followed by a second in 1994 -1999 by the 26th Ephorate of Prehistoric and Classical Antiquities and the Department of Restoration of Ancient Monuments.
According to the findings, the Roman Odeon of Kos seems to have been built between 1st and 2nd century AD in the place of an earlier public building, which was allegedly the Senate of the city. The purpose of its creation was to present musical contests, but it functioned as the seat of the Senate for honour to distinguished citizens of Kos.
The building was originally roofed and could accommodate about 750 people. Its hollow is oriented to the north and supported on vaulted structures and had fourteen rows of marble seats. Two galleries and rooms, used as shops or as workshops, had been created beneath the hollow.
It was in an irregular pentagon shape and consisted of two parts, the foreground and background, while the orchestra was circular and its floor was decorated with marble inlays. 18 marble statues were found during the excavations, the most important being that of Hippocrates, which is now housed in the Archaeological Museum of Kos.