Kalemegdan is a huge park right in the centre of Belgrade. It has everything. Amazing views, the zoo is right next to it, view of the Danube, fortress (huge castles) and so on. It has ride for little kids, and at almost every corner there is a pop-corn stand or ice cream stand. The park is for everyone, not just families. Lots of couples go there too because of the amazing sights when the sun goes down, it's very romantic. Also there is a display of army tanks.