The Berlin Wall was not one wall, but two. Measuring 155 kilometres (96 miles) long and four metres (13 feet) tall, these walls were separated by a heavily guarded, mined corridor of land known as the 'death strip'.

The Berlin Wall was not a single structure but a complex defensive system that evolved significantly over its 28-year existence, reaching its most famous form, the "Border Wall 75," in the mid-1970s. This final version consisted of L-shaped concrete segments that stood approximately 3.6 to 4 meters (roughly 12 to 13 feet) tall. These segments were topped with a smooth, rounded concrete pipe designed to make it nearly impossible for escapees to get a grip on the top. However, the height of the wall was only one part of the deterrent; the "inner wall" facing East Berlin was often slightly shorter, and between the two walls lay the "Death Strip." This gap featured sand to show footprints, tripwire-activated flares, fierce guard dogs on long runs, and over 300 watchtowers manned by armed guards with orders to shoot. While 13 feet might seem surmountable with a ladder, the combination of the height, the rounded top, and the lethal no-man's-land behind it made the Berlin Wall one of the most effective and infamous barriers in modern history until its fall in 1989.