Plovdiv (Bulgarian: Пловдив) is the second-largest city in Bulgaria, and one of the oldest cities in Europe. It is located in the large plain between the Rhodope Mountains in the south of Bulgaria and the Balkan Range, or Old Mountains (Stara Planina) that runs through the center of Bulgaria. Both ranges are visible on clear days. The Maritsa River flows through the city on its way southeast before forming the Greek/Turkey border to the Aegean Sea.
Plovdiv, the oldest continuously-inhabited city in Europe, is now located on six hills. The first Thracian settlement on Nebet hill has been dated back to 6000 BC. The first inhabitants of the city were supposedly Thracian tribes - the bessi and odrisi. In 342 BC Philip of Macedon conquered the city and gave it the name Philippopolis ("Philippos" and "polis" - city). In 12 AD, the Romans started conquering the Thracian provinces on the territory which is now Bulgaria. After the death of the Thracian king Remetalk in 46 AD, Thracia was officially proclaimed a Roman province. During this period, the city of Plovdiv was an important administrative center and soon afterwards it was proclaimed a metropolitan city of the province Thracia. The city was called Trimontium (a city on three hills) but soon it regained its previous name Philippopolis. During the long occupation by the Ottoman Empire, a large mosque was built, still present in the centre area as well. During communist times, a statue of the unnamed Russian soldier was erected on one of the three main hills which overlooks the city.