|Hrvatska Kostajnica in Croatia|
The fortress was built most probably in the 14th century and owned by the members of the noble families Frankopan, Lipovečki, Tot, Benvenjud and finally (in the 16th century) Zrinski, so it is today also known as "Zrinski fortress" or "Zrinski castle" (Croatian: Stari grad Zrinski). It was conquered by the Ottomans on 17 July 1556, but it was freed from their rule relatively fast, in 1688.
Situated on the banks of the river Una, the fortress has very strong walls and three towers. Having been in a state of disrepair before, it has been renewed in recent years by the Croatian Ministry of Culture.
- Kruhek, Milan (2001). "Kostajnica u protuturskoj obrani Hrvatskoga Kraljevstva" [Kostajnica in the Anti-Turkish defense of the Croatian Kingdom] (PDF). Povijesni prilozi (in Croatian). Croatian Institute of History. 20 (21): 71–97. Retrieved 27 July 2020.
- Miletić, Drago; Valjato Fabris, Marija (2011). "Stari grad u Hrvatskoj Kostajnici. Konzervatorsko-restauratorski radovi do završne prezentacije" [Old Town in Kostajnica: conservation and restoration works – from the onset to the final presentation] (PDF). Portal (in Croatian). Croatian Conservation Institute (2): 35–53. Retrieved 20 October 2020.
- Nadilo, Branko (2003). "Stari grad na unskom otoku u Kostajnici" [Old town on the Una island in Kostajnica] (PDF). Građevinar (in Croatian). Croatian Association of Civil Engineers. 55 (6): 363–369. Retrieved 20 October 2020.
|Wikimedia Commons has media related to Kostajnica Fortress.|
- The town of Croatian Kostajnica
- Official tourist information page
- An outline of the archaeological topography of the Kostajnica and Dvor region