The Ralja is a river in Šumadija

Šumadija

Šumadija is a geographical region in Serbia. The area is heavily covered with forests, hence the name...

 region of Serbia

Serbia

Serbia , officially the Republic of Serbia , is a landlocked country located at the crossroads of Central and Southeast Europe, covering the southern part of the Carpathian basin and the central part of the Balkans...

, a 51 km-long left tributary to the Jezava, the left arm of the Velika Morava

Velika Morava

The Great Morava is the final section of the Morava , a major river system in Serbia.- Length :...

 river. It also gives its name to the surrounding Šumadija's subregion

Subregion

A subregion is a conceptual unit which derives from a larger region or continent and is usually based on location. Cardinal directions, such as south or southern, are commonly used to define a subregion.- United Nations subregions :...

 of Ralja.

The Ralja originates from the northern part of the Kosmaj

Kosmaj

Kosmaj is a mountain south of Belgrade, the capital of Serbia. With an elevation of 626 meters, it is the highest point of the entire Belgrade City area and is nicknamed one of two "Belgrade mountains" .- Location :The Kosmaj, is located 40 kilometers south-east of Belgrade...

 mountain, north of the village of Velika Ivanča

Velika Ivanča

Velika Ivanča is a village situated in Mladenovac municipality in Serbia....

, in the Sopot

Sopot, Serbia

Sopot is a town and municipality in Serbia. It is part of the wider region of Belgrade, located south of Belgrade at , 177.38 m above sea level. Its name is the old Slavic word for spring which is today replaced in Serbian by the word 'извор'.Sopot is near the mountain Kosmaj...

 municipality of the City of Belgrade

Belgrade

Belgrade is the capital and largest city of Serbia. It is located at the confluence of the Sava and Danube rivers, where the Pannonian Plain meets the Balkans. According to official results of Census 2011, the city has a population of 1,639,121. It is one of the 15 largest cities in Europe...

. Almost from the source, the river valley is a route for the Belgrade-Niš

Niš

Niš is the largest city of southern Serbia and third-largest city in Serbia . According to the data from 2011, the city of Niš has a population of 177,972 inhabitants, while the city municipality has a population of 257,867. The city covers an area of about 597 km2, including the urban area,...

 railway. At the villages of Popović

Popovic

-Popovich:Popovich or Popovitch is a common Ukrainian or Russian surname, and sometimes a patronymic meaning son of Popov...

 and Mali Požarevac

Mali Požarevac

Mali Požarevac is a village in the municipality of Sopot, Serbia. According to the 2002 census, the village has a population of 1479 people.-References:...

, the Ralja turns straight to the east for the rest of its flow and also from this point, the Belgrade-Niš highway joins the railroad.

As it flows next to the Belgrade suburbs of Dražanj

Dražanj

Dražanj is a suburban settlement of Belgrade, the capital of Serbia. It is located in the municipality of Grocka.Dražanj is located in the southern part of the municipality, in the northern Šumadija region, between the macro-region of Podunavlje and northeastern slopes of the Kosmaj mountain...

, Umčari

Umcari

Umčari is a suburban settlement of Belgrade, the capital of Serbia. It is located in Belgrade's municipality of Grocka.Umčari is located in the southeastern part of the municipality, in the northern Šumadija region...

 and Živkovac

Živkovac

Živkovac is a suburban settlement of Belgrade, the capital of Serbia. It is located in Belgrade's municipality of Grocka....

, the Ralja divides Podunavlje

Podunavlje

Podunavlje is the name of the Danube river basin parts located in Serbia and Croatia .-History:...

 region from the Ralja region of the low Šumadija, and leaves the City of Belgrade area at the village of Malo Orašje. After the villages of Binovac, Kolari, Vrbovac and Ralja, the river separates from the highway turning north at the village of Vranovo

Vranovo

Vranovo is a village in the municipality of Smederevo, Serbia. According to the 2002 census, the village has a population of 2682 people....

 and empties into the one of several arms of Jezava at the Smederevo

Smederevo

Smederevo is a city and municipality in Serbia, on the right bank of the Danube, about 40 km downstream of the capital Belgrade. According to official results of the 2011 census, the city has a population of 107,528...

's suburb of Radinac

Radinac

Radinac is a town in the municipality of Smederevo, Serbia. According to the 2002 census, the village has a population of 4920 people....

.

The Ralja drains an area of 310 km², belongs to the Black Sea

Black Sea

The Black Sea is bounded by Europe, Anatolia and the Caucasus and is ultimately connected to the Atlantic Ocean via the Mediterranean and the Aegean seas and various straits. The Bosphorus strait connects it to the Sea of Marmara, and the strait of the Dardanelles connects that sea to the Aegean...

 drainage basin

Drainage basin

A drainage basin is an extent or an area of land where surface water from rain and melting snow or ice converges to a single point, usually the exit of the basin, where the waters join another waterbody, such as a river, lake, reservoir, estuary, wetland, sea, or ocean...

and it is not navigable.