The Old Belgrade Fairground complex is the large area in the center of Belgrade that is completely isolated from other parts of Belgrade: it is one of the most devastated city areas, populated by poor inhabitants, often by those from the marginal groups, burdened with tragic history and it represents one of hardest problems for planners to solve. It is situated on the left bank of the Sava River between two bridges and downtown New Belgrade. Opposite to it, the Sava Amphitheater slopes down the Belgrade Ridge towards the river. The complex was built in the thirties of the 20th century across the River Sava in the area that was an unpopulated swamp - Belgrade was situated on the right Sava bank. It was meant to be modern extension of oriental city, which could represent the western tendencies of the young state (Kingdom of Yugoslavia) and its capital. Modern and monumental complex of exhibition and commercial pavilions was built, and started its life with national and international fairs and exhibitions. World War 2 changed its destiny: German occupation forces transformed the complex into the concentration camp, where thousands of people were tortured and killed. After the war, new republican government, both communist and antifascist, had double frustration regarding this space: it’s tragic (during the War) and "capitalist" (before the War) past, so complex that was absolutely ignored in the period of the postwar renewal, and the result is described at the beginning of this text. This paper discusses the possibility to conciliate historical roles of the complex, and to realize it’s potentials in the modern world. Facts of the complex’s history are presented in the first part of the paper. Further on, these facts are analyzed in the context of contemporary city development of Belgrade in particular but globally, too.. Finally, some guidelines for crossing the gap between this area and the rest of the city are presented in the third part of the paper.