Gradačac Castle (Bosnian, Croatian and Serbian: Gradačačka tvrđava / Градачачка тврђава) is a castle in Gradačac in Bosnia and Herzegovina. Gradačac Castle is 138 m above sea level. Gradačac Castle has a fort with walls 18 m high, built between 1765 and 1821, and a watchtower 22 m high, built in 1824 by Husein Gradaščević on foundations made originally by the Romans. It was finished in the 19th century. In 1831 general captain Husein Gradaščević rallied the Bosnians against the Ottoman occupation and drove the Ottomans out of Bosnia all the way to Kosovo, winning Bosnia its sovereignty for the coming year. Therefore, fortification has great historic importance for Bosnians. It has been recently renovated.