Gagai was an ancient city located in the Antalya province of Turkey. It was founded in the Hellenistic period and was an important city during the Roman and Byzantine periods. The city was situated on a hill and had a castle, a theater, and a temple dedicated to the god Apollo. The city was also known for its production of wine and oil. Today, the ruins of the city can still be visited and many artifacts from the ancient city can be seen at the Antalya Museum.