The Central Taurus Mountains are roughly defined to include northern Mersin Province and northwestern Adana Province. The highest point in the Central Taurus is Mt. Demirkazık (3,756m). The Cilician Gates or Gülek Pass has been the principal pass through the Eastern Taurus since ancient times, connecting the coastal plain of Cilicia with Central Anatolia. The Tarsus-Ankara Highway (E90, O-21) passes through it. Mountain ranges in the Central Taurus include: