Ada Ciganlija Lake

Belgrade's "sea" — a dammed side channel of the Sava, now a current-free lake inside the city. Where most Serbian divers do their first open water dives.

Roughly 4.2 km long, mostly 8-9 m deep with holes reported to 12–13 m. Soft silt bottom, so watch your trim. Visibility drops to under a metre in swimming season and opens up to 4–5 m in spring and late autumn. Fish life is carp, catfish, pike, zander, crayfish and turtles.

Not scenic, but unbeatably convenient: park, kit up, walk in. Good for training, gear shakedowns, night dives, and ice diving in hard winters.