Prozor Fortress (Croatian: Tvrđava Prozor or Gradina) is a medieval fortress situated in the continental part of Split-Dalmatia County, in inland Dalmatia, just above the town of Vrlika in Croatia. From its origin as a small stronghold built by the ancient Illyrian tribe Dalmatae, it developed into a fortress in the 15th century, during the reign of the Croatian and Bosnian feudal lord Hrvoje Vukčić Hrvatinić.