It is located above the river Kupa in Ozalj. It was first mentioned in 1244, although objects from prehistoric and Roman times were also found on that hill.
The oldest preserved parts of the castle are the square defensive tower at the entrance, the Gothic chapel and the Zrinski Palace.
The castle is notable for the fact that the Croatian ban Petar Zrinski, his wife Katarina and her brother Fran Krsto Frankopan lived and ruled from it. They were one of the leading intellectuals and writers of their time. This makes Ozalj the center of Croatian politics and culture of that time.