Tarsus was the capital of ancient Cilicia and is best known as the city where the apostle Paul was born. At that moment, the city was already fifteen centuries old: it is mentioned for the first time in a Hittite text from c.1450 BCE. It was subjected to the Hittites and to the Assyrians, was occupied by Nabonidus of Babylonia, conquered by the Persians and by Alexander the Great, was part of the Seleucid, Roman, and Byzantine Empires, and was the object of much warfare between the Muslims, Byzantines, and Crusaders.
The site remains occupied to the present day, which explains why there are not many monuments to be seen. Still, there’s a Byzantine bridge, a gate, and a small set of beautiful mosaics, now in the Archaeological Museum of Antioch. My own page is available here.