The inner German border (Innerdeutsche Grenze, Deutsch-Deutsche Grenze, or Zonengrenze) ran the entire 1,381-kilometer (858 miles) length of the border between East Germany (the German Democratic Republic, or GDR) and West Germany (the Federal Republic of Germany, or FRG).
(The border was a series of 3–4-metre (12–15 ft) high metal fences, walls, armed guards, guard dogs, barbed wire, electric alarms, trenches, watchtowers, automatic guns and minefields. The Berlin Wall, which separated East and West Berlin, was the most famous part of the system but it formed less than a tenth of the whole. Nowadays, most of the system is a green haven for wildlife.)