first exhibit in the predecessor of the modern Aeronautical Museum Belgrade. Today, the area is used by the parachutists and paragliders and as the location of the air shows for sports and ultra-light aviation. In June 2021 it was announced that the memorial bench dedicated to Rusjan will be placed below the fortress and that surrounding green area will be named the Edvard Rusjan Park. The fortress and the park were damaged during World War I. Serbian army had no proper weaponry to fight the Austro-Hungarian gunboats, so they freely fired at the city from the Sava. The city was especially damaged during the heavy bombardment in 1914–1915. Diplomat and author described it in 1914: "Kalemegdan is "trimmed", the trees in the park are battered, the ancient ramparts of Singidunum crushed, all being hit by the heavy, modern artillery, from precisely measured distance and even more precisely unmeasured hatred". Heavy fighting occurred in the Lower Town in 1915, when Serbian forces, led by major Dragutin Gavrilović, persistently but ultimately unsuccessfully, fought the invading Austro-Hungarian army. Before full occupation, Austro-Hungarian army temporarily entered Belgrade, from 3 to 14 December 1914. Already on 4 December they erected gallows in fortress' Upper Town, and on several other locations around the town, for hanging civilians. In 1928, building company "Šumadija" proposed the construction of the cable car, which they called "air tram". The project was planned to connect Zemun to Belgrade Fortress, via Great War Island. The interval of the cabins was set at 2 minutes and the entire route was supposed to last 5 minutes. The project was never realized, but the idea of the cable car was revived in the 21st century. Funiculars were also planned, to connect the Upper and the Lower Town. The entire Lower town was planned for demolition, with the plans including large amusement park, museums, artificial lake, zoo, and stadiums instead of the existing military barracks. Instead of everything, the railway was conducted around the foothills of the fortress, encircling it completely, and effectively cutting it off from the Sava river, which wasn't universally accepted among the architects and urbanists of the day. During his visit to the 1936 Berlin Olympics, Yugoslav prime minister Milan Stojadinović was fascinated by the objects built for the games, especially by the grandiose Olympic Stadium. He instigated the Yugoslav Olympic Committee to nominate Belgrade as the host of the 1948 Olympics