• The wall went up on August 13th 1961. However, it was only a barbed wire fence at first.
  
• Between August 1961 and the end of the year the wall was extended considerably. The first stage was the building of a concrete wall. Then space was cleared either side of the wall. The spaces were patrolled by armed guards and dogs. There were also towers with searchlights.
  
• This document comes from a Foreign Office report which was passing on information provided by military observers at the wall.
  
• The Brandenburg Gate was in the very heart of Berlin, near the crossing point known as Checkpoint Charlie.