The term that refers to this Battlefield is the Eastern Front. "The Eastern Front was a theatre of war during World War I in Central and, primarily, Eastern Europe. The term is in contrast to the Western Front. Despite the geographical separation, the events in the two theatres strongly influenced each other." The above was quoted from Wikipedia.
Eastern Front
Russia began moving it's army toward the russian-Austrian border. it mobilized Russia along the German border
La ligne Maginot was a defensive line along the German border.
The Oder River.
Georgia, Stalin was born in Gori, Georgia
The Maginot Line was a line of French fortifications along the French/German border.
The East German Army Engineering Command built the Berlin Wall, and also the fortifications along the inter-German border.
Tian Shan. It was Russian-Chinese border before 1990's. Now it's the border between China and Central Asian countries.
The Maginot Line
Top right (North-East) along the river Rhine on the German border
The Russian troops mobilized to the Russo-german border, as Russia was involved in near war with Germany's ally, Austria-Hungary. That, along with said alliance, brought Germany into the war that would, forty years later, be called Wolrd War I.
German troops crossed through Belgium in an attempt to flank the French forces lined in trenches along the border.