Berlin Wall
The infamous Berlin Wall separating East and West Berlin came down on November 9, 1989 after standing for over 28 years, and a chunk of it can be viewed at the Ronald Reagan Presidential Library in Simi Valley. This section weighs 6,338 lbs and stands 9 1/2 ft tall. At this spot you also have a great view of the surrounding countryside.
Links: Ronald Reagan Presidential Library previous related post