https://www.beozoovrt.rs/home-page/
The Belgrade Zoological Garden works all 365 days of the year. The ticket office is open from 08:00-19:00 . The tickets are sold until half an hour before the beginning of dusk. The ticket prices: adults (over 15 years of age) 500 dinars per person; children (from 3 to 15 years of age) 300 dinars per person; students' excursions (over 15 persons) 250 dinars per person.