The Berlin Wall was a barrier that divided Berlin from 1961 to 1989. Constructed by the German Democratic Republic starting on 13 August 1961, the wall completely cut off West Berlin from surrounding East Germany and from East Berlin until it was opened in November 1989.
This is one segment of the wall still standing and is now a memorial to the people who lost their lives trying to cross into West Berlin. Reports estimate the death toll from 136 to more than 200 in and around Berlin.
Information from wikipedia