Ephesus (Hittite Apasa; Ancient Greek ; Turkish Efes) was a city of ancient Anatolia. During the period known as Classical Greece it was located in Ionia, where the Cayster River (Küçük Menderes) flows into the Aegean Sea. It belonged to the Ionian League.

Ephesus hosted one of the seven churches of Asia, addressed in the Book of Revelation of The Bible), and the Gospel of John might have been written here. Harris, Stephen L., Understanding the Bible. Palo Alto: Mayfield. 1985. It is also the site of a large gladiator graveyard.

Today's archaeological site lies 3 kilometers south of the Selçuk district of İzmir Province, Turkey. The ruins of Ephesus are a favorite international and local tourist attraction, partly owing to their easy accessibility from Adnan Menderes Airport and via the port of Kuşadası.