The river Danube and the South Dobrogea.
The northern boundary of Bulgaria that separates it from Romania is the Danube River. The Danube River is a very important river that flows through several countries before it reaches the Mediterranean Ocean.
the country that forms the northern boundary of the United States is Canada :)
This is the river Danube.
This boundary is mainly Danube; and a in the South of Dobrogea a terrestrial border.
Carpathian Mountain
This is the river Danube.
The sea that forms the northern boundary of Africa is the Mediterranean Sea. The countries of Morocco, Algeria, Tunisia, Libya and Egypt border it.
The western boundary of Romania is with Hungary.
red river
The Arctic Ocean
The sea that forms the northern boundary of Africa is the Mediterranean Sea. The countries of Morocco, Algeria, Tunisia, Libya and Egypt border it.