Belgrade Zoo sits inside the Kalemegdan area, an unusual location that puts animal enclosures, fortress walls, and river views almost on top of each other. It is compact and very central, so it is easy to fold into a visit to the fortress rather than treating it as a separate excursion.
The zoo is most useful for families or for travellers with extra time in the park. Standards and enclosure styles vary, so come with realistic expectations, but the setting is distinctive and the walk between the fortress, zoo, and viewpoints gives a good sense of old Belgrade's high ground.