Riverside introduction: The Sava River and the Donau are the most important rivers in Belgrade, and the two rivers also meet here. The Sava River is the largest tributary on the right bank of the Danube River. It has many canyons in its upper reaches and is rich in water resources. The Danube River is the river that flows through the most countries in the world and is also one of the world's most famous and important rivers. It is used as the background for many artistic works.