One of the most important public buildings of the ancient city of Kos is the restored Roman conservatory today. It is located south of the western archeological site, west of the also restored Roman house (Casa Romana) and northwest of the ancient theater. According to information, which we draw from ancient inscriptions, the conservatory took the place of an earlier public building, which probably served for the gatherings of the municipality of Kos and may have been the city hall. 

The conservatory was built in the 1st-2nd c. μ.X. and was intended for holding musical competitions, while it also functioned as the seat of the Senate, the public body of Kos, which, according to the inscriptions, had no political powers, but took care of paying tribute to distinguished citizens of the island.