Border in Thuringia (1971) After the GDR began to close off the inner-German border in the 1950s, an elaborate system of border controls was constructed and brought to deadly perfection in the 1960s. Control zones of up to 5 kilometers in width were outfitted with mines, barriers, fences, patrol paths, and spring guns. This picture shows the border in Thuringia in 1971 (view from the East). Photographer unknown.