The East German side of the inner German border was dominated by a complex system of fortifications and security zones, over 1,300 kilometres (810 mi) long and several kilometres deep. The fortifications were established in 1952 and reached a peak of complexity and lethality at the start of the 1980s. The border guards referred to the side of the border zone facing the GDR as the freundwärts (literally "friendward") side and that facing the FRG as the feindwärts ("enemyward") side.[55]