Belgrade offer great cycling opportunities mainly alongside its rivers. All trails are connected and there is even cycle elevator on the Brankov Bridge so one can cross Sava and continue cycling on the other side. Only interruption on these trails is currently bellow new bridge over Ada (there are improvised stairways) but hopefully this short part will be connected again once all works on new bridge get finished. There are several bicycle services on trails which also rent cycles. Wonderful panorama on Belgrade is from both sides and there are plenty of fine boat-restaurants on rivers.