The ancient city of Ephesus, which witnessed the Neolithic, Hellenistic and Roman ages, is located in Izmir province of Turkey. The foundation of the city goes back to the Neolithic Age, around 6000 BC. Ephesus was one of the twelve cities of Ionia during the Classical Greek period. During that period, every part of the city was decorated with monumental structures made of marble. The ruins located in four main areas as Ayasuluk Hill, Artemision, Ephesus and Selcuk are visited by an average of 1.5 million tourists every year. After being included in the World Heritage Tentative List by UNESCO in 1994, Ephesus was registered as a World Heritage in 2015.