<Li> <P> Short section of the Berlin Wall at Potsdamer Platz, March 2009 </P> </Li> <P> Short section of the Berlin Wall at Potsdamer Platz, March 2009 </P> <Li> <P> Souvenir chunk of concrete from the Wall </P> </Li> <P> Souvenir chunk of concrete from the Wall </P>

Who is responsible for the building of the berlin wall