Stara Zagora is a city in Bulgaria, and the administrative capital of Stara Zagora Province. It is located in the Upper Thracian Plain, near the cities of Kazanlak, Plovdiv, and Sliven. Its population is 121,582 making it the sixth largest city of Bulgaria, located North East of Plovdiv. The city has had different names previously, including Beroe, Borui, Irenepolis, Eski Zagra, Augusta Traiana, etc. The earliest traces of civilisation date back to the 7th millennium BC. Some scholars believe that the ancient Thracian city of Beroe was located on the present site of Stara Zagora.