Ostrovica is a small village named after a small river (tributary of the Una) in the Una-Sana Canton of Bosnia and Herzegovina, located on a hill near the town of Kulen Vakuf.
In the Middle Ages, Ostrovica was a fort, first mentioned in 1407 as a property of Sandalj Hranić, who in turn had received by marrying a woman from the House of Hrvatinić. He sold it to the Republic of Venice in 1411, who held it until it was taken by the Ottoman Empire in 1501. In 1737, the fort was unsuccessfully besieged by the army of the Habsburg Empire.[1]