On the Una, the border river between Croatia and Bosnia-Herzegovina, lies the small town of Kostajnica. The name refers to the speciality of the village: chestnuts from the dense chestnut forests that surround it.

At the beginning of October, fans of the Middle Ages and chestnuts meet in the municipality for a big festival. Archery competitions, sword fights or dance performances in historical costumes are organised.
There are processions, guided tours of the old town and musical performances.

Everywhere in the city there is the smell of freshly roasted chestnuts, but also other agricultural products such as honey or cheese can be tasted and bought.
The local brewers serve delicious chestnut beer.