The Morava (German: March, Hungarian: Morva, Polish: Morawa) is a river in Central Europe, a left tributary of the Danube. It is the main river of Moravia, which derives its name from it. The river originates on the Králický Sněžník mountain in the north-eastern corner of Pardubice Region, near the border between the Czech Republic and Poland and has a vaguely southward trajectory. The lower part of the river's course forms the border between the Czech Republic and Slovakia and then between Austria and Slovakia.
The lowlands formed by the river are the Upper Moravian Vale or Hornomoravský úval and then the Lower Moravian Vale or Dolnomoravský úval in Moravia, the Moravian Field or Marchfeld in Lower Austria, and the Záhorie Lowland or Záhorská nížina in Slovakia. The latter three are actually continuous parts of one large basin, forming the major part of the Vienna Basin.
In the Czech Republic, there are some larger towns lying upon Morava, particularly Olomouc, Kroměříž, Otrokovice, Uherské Hradiště and Hodonín. Downstream from here, the river flows along sparsely inhabited, forested border area, all the way to its outfall into the Danube, just below the Devín Castle at the outskirts of the Slovak capital Bratislava. After 354 km of its course, Morava feeds the Danube by an average discharge rate of 120 m3/s, gathered from a drainage area of 26 658 km2. The Morava river is unusual in that it is a European blackwater river.
The Great Morava (Serbian: Велика Морава / Velika Morava, pronounced [vêlikaː mɔ̌rava]) is the final section of the Morava (Cyrillic: Морава), a major river system in Serbia.
The Velika ("Great") Morava begins at the confluence of the South Morava and the West Morava, located near the small town of Stalać, a major railway junction in central Serbia. From there to its confluence with the Danube northeast of the city of Smederevo, the Velika Morava is 185 km long. With its longer branch, the West Morava, it is 493 km long. The South Morava, which represents the natural headwaters of the Morava, used to be longer than the West Morava, but due to the regulations of river bed and melioration, it is shorter nowadays.
At one time (regulations were made on all three branches making them shorter) the Morava was over 600 km long. Today, the most distant water source in the Morava watershed is the source of the Ibar River, the right and longest tributary of the Zapadna Morava, originating in Montenegro, which gives the Ibar-West Morava-Great Morava river system a length of 550 km, which still makes it the longest waterway in the Balkan Peninsula.