Belgrade, Serbia

Belgrade, the capital of Serbia with roughly 1.4 million residents, occupies a 125-metre ridge at the confluence of the Danube and Sava rivers. Settlements on this site have been traced back some 7,000 years, placing it among the oldest continuously inhabited cities in Europe. The Belgrade Fortress anchoring that ridge has been destroyed and rebuilt 115 times across 16 separate campaigns, a record few European strongholds approach. From its gates, the 870-metre pedestrian street of Knez Mihailova follows the line of a former Roman cardo down to Republic Square. What those layered ruins still conceal is only beginning to surface.