Dezful (, pronounced , Dezfuli dialect: Desfil, pronounced ) also Romanized as Dezfūl and Dezfool; also known as Dīzfūl and Ab I Diz is a city and capital of Dezful County, Khuzestan Province, Iran. At the 2011 census, its population was 420,000 people in 105,000 families. In 2006, the city had 228,507 inhabitants. Dezful is located 721 kilometers away from the national capital of Tehran and 155 kilometres away from the provincial capital of Ahvaz. The city is located 300 kilometres from the Persian Gulf and is at an altitude of 143 meters. The city is located at the foot of the Zagros Mountains and has a history that dates back to the Sassanian era. The area around Dezful has been home to civilizations for 5000 years. Located in an area with a history that extends back to ancient civilization, the city houses a bridge that dates back to 300 AD. Etymology The name Dezful has been derived from the two words diz (fortress) + pul (bridge), which in combination could stand for 'the bridge to the fortress' or 'fortified bridge'. The original name of the city was Dezhpul, but after the Muslim conquest of Persia, the city was renamed Dezful, since the Arabic language does not have 'p' and 'zh' sounds. History Dezful is one of the oldest cities in the Khuzestan province. According to Walther Hinz excavations, Awan (capital of the first Elam empire) was located in Dezful. The bridge was built during the reign of Shapur I who used Roman prisoners of war after the Battle of Edessa to build the bridge. People The people of Dezful, known as Dezfuli, Dezfoolians or Dezfulians, speak Dezfuli – a dialect distinct to Dezful – and Shushtari, which is sometimes considered the most archaic of Persian dialects. Geography Dezful sits close to the foothills of the Zagros Mountains on the main north-south highway from Tehran to Ahvaz, the provincial capital of Khuzestan. The main rail line from Tehran to the Persian Gulf is 15 km (9 mi) from Dezful, on the opposite side of the Dez River. Climate Dezful has a hot semi-arid climate (Köppen climate classification BSh) with extremely hot summers and mild winters. Rainfall is higher than most of southern Iran, but is almost exclusively confined to the period from November to April, though on occasions it can exceed per month or per year. Transportation There are direct