Adana is a major city in southern Turkey. The city is situated on the Seyhan river, inland from the Mediterranean, in south-central Anatolia. It is the administrative seat of the Adana Province and has a population of 1.7 million, making it the fifth most populous city in Turkey. Adana-Mersin polycentric metropolitan area, with a population of 3 million, stretches over east-west and north-south; encompassing the cities of Mersin, Tarsus and Adana. Adana lies in the heart of Çukurova, a geo-cultural region alternatively known as Cilicia. Home to six million people, Çukurova is one of the largest population concentrations in Turkey, as well as the most agriculturally productive area, owing to its large stretch of flat, fertile land. Region covers the provinces of Mersin, Adana, Osmaniye, and Hatay.