Ostrovica medieval fortress in National Park Una above Kulen Vakuf, Bosnia and Herzegovina

Area of the park has rich cultural-historic heritage and numerous archaeological sites, many dating from the prehistoric period. Significant historical and cultural heritage of the area within and outside the park zone are the Roman fort Milančeva Kula, Rmanj Monastery, medieval fortress Ostrovica above Kulen Vakuf, as well as outside the park zone Sokolačka Kula fortress in Sokolac village near Bihać and Ostrožac Castle between Bihać and Bosanska Krupa.