What's worth your time in Belgrade
Belgrade rewards visitors who read it as a layered city rather than a checklist. Two thousand years of Roman, Ottoman, Habsburg, and socialist-modernist history sit on top of each other at the confluence of the Sava and Danube — and most of what's worth seeing is walkable from the old town. Start at Kalemegdan and the Belgrade Fortress, follow the Knez Mihailova promenade through Stari Grad, and leave time for the neighborhoods that give the city its character: creative Dorćol, post-industrial Savamala, bohemian Skadarlija, and the old Habsburg river town of Zemun. Three days is the honest sweet spot for a first trip.