Obedska Bara is a slow, green counterweight to Belgrade: an old meander of the Sava River turned into a wetland reserve of reedbeds, willow, water, and birdlife. It is not spectacular in the cliff-and-waterfall sense, but it is one of the better nature escapes within reach of the capital.
The reserve suits birders, patient walkers, and travellers with a car who want to see the lowland landscapes west of the city. Expect quiet trails and seasonal variation rather than polished visitor infrastructure.