Toast the sunset from Belgrade's Kalemegdan Citadel

SERBIA // Looming over Belgrade, the 1500-year-old Kalemegdan is more than a scenic stronghold: it's a glorious time machine. Strategically positioned above the confluence of the Sava and Danube Rivers, it has been fought over by countless invaders over the centuries. The juxtaposition between its gory history - evident in still-standing prison gates, torture towers and a military museum - and today's boho cafes, tennis courts and chess players, makes Kalemegdan simply spellbinding.