Efes (Ephesus) was an ancient Greek city, and later a major Roman city, near present-day Selçuk. In the Roman period, it was for many years the second largest city of the Roman Empire; ranking behind Rome, the empire's capital. Efes had a population of more than 250,000 in the 1st century BC, which also made it the second largest city in the world.
The city was famed for the Temple of Artemis, one of the Seven Wonders of the Ancient World, and the largest building of the ancient world. Efes was also well known for the Library of Celsus, which held almost 12,000 scrolls, as well as its theatre, which was capable of holding 25,000 spectators. This open-air theater was used initially for drama, but during later Roman times gladiatorial combats were also held on its stage.