Adiyaman is a city located in southeastern Turkey and is the capital of Adiyaman Province. It is one of the fastest growing cities in Turkey. The city officially had the Ottoman Turkish name Hısn-ı Mansur ("Mansur Castle") until 1926, named after the fortified castle located on a hill around which the city grew. Since the official name was difficult for locals to pronounce, people had been referring to the city as adiy yaman since the early 19th century, which means "its name is difficult" or "(the place) whose name is difficult" in Turkish.