Yumuktepe (modern Mersin), which guards the Adana side of the gateway, with 23 layers of occupation, is at 4,500 BCE, one of the oldest fortified settlements in the world.

This may explain why one of the world's oldest fortresses was built at the southeastern end of the Cilician Gates around 4500 BCE.

Below the Cilician Gates is the medieval Armenian fortress of Anahşa with its large horseshoe-shaped towers and three entrances.

[6] Also in the vicinity of the Gates is a fort built in the 1830s by Ibrahim Pasha of Egypt during his Syrian campaign against the Ottomans.

The series of viaducts and tunnels they built are among the marvels of railroad engineering;[8] this route actually follows an ancient secondary road southeast from Pozantı, below Anahşa Dağı with its medieval Armenian fortress.