Beneath Kopački Rit's waters lie 44 species of fish, including carp, bream, pike, catfish and perch. Above the water buzz 21 kinds of mosquito (bring repellent!) and on land roam red deer, wild boar, beaver, pine marten and foxes. But it’s really about the birds here – look for the rare black storks, white-tailed eagles, great crested grebes, purple herons, spoonbills and wild geese. The best time to come is during the autumn migration.
The park was heavily mined during the war and closed for many years as a result. Most mines have now been cleared and safe trails have been marked. The park visitor centre, located at the main entrance, along the Bilje–Kopačevo road, features a lovely interpretation centre in a string of straw-roofed wooden huts that house interactive exhibits and a cafe. You can walk the 2km series of wooden boardwalks and then take a boat tour on Sakadaško lake. A tour by big boat, taking in a castle complex along the way, costs 80KN for adults and 60KN for children and students; a wildlife tour in a small boat is 100KN per hour (maximum four people) and by canoe 80KN. Tours depart from an embarkation point on the lake about 1km from the visitor centre (at the end of the boardwalk area). Book at the visitor centre when you arrive.
At the northern end of the park, 12km from the visitor centre, is an Austro-Hungarian castle complex and bio-ecological research station, Dvorac Tikveš. Once used by Tito as a hunting lodge, the castle was occupied by Serbs during the 1990s and forests around the complex are still mined – don’t wander off by yourself.
Kopački Rit Nature Park visitor centre rents bikes (20/100KN per hour/day) so that you can explore the rural area surrounding the inner wetlands.
Bilje, 5km north of Osijek, is a dormitory suburb for the city, with a clutch of accommodation options. It makes an alternative base for exploring Kopački Rit. Both family-run B&Bs Mazur and Crvendać are good bets here. Zlatna Greda is a nature-lover's alternative on the park's edge, with hostel-type accommodation.
The villages surrounding Kopački Rit Nature Park have several excellent country restaurants that serve regional specialities, such as river fish and game-meat stews.