The Military Museum inside Kalemegdan fortress covers Serbian and Yugoslav military history from the Roman period to the 1990s conflicts, with an emphasis on the First and Second World Wars. The collection includes weapons, uniforms, medals, artillery pieces, and maps documenting the campaigns in which Serbia played an outsized role — including the Serbian retreat through Albania in 1915-16, one of the most catastrophic and least known episodes of the First World War.
The outdoor section, on the fortress ramparts, displays captured artillery, tanks, and aircraft from various conflicts, with views over the Danube and Sava rivers as backdrop. The museum tends to be less crowded than the fortress park itself and rewards a visit for anyone interested in military history or the extraordinary disruptions of the 20th century in this part of Europe.