Norman Foster, "Reichstag Dome", 1993, a glass dome constructed on top of the rebuilt Reichstag building, symbolizing the reunification of Germany. A mirrored cone in the center of the dome directs sunlight into the building, and so that visitors can see the working of the chamber, Berlin, Germany.
Book Burning Memorial - In the center of Bebelplatz, a glass window showing rows and rows of empty bookshelves. The memorial commemorates the night in 1933 when 20,000 "anti-German" books were burned. There's a plaque nearby that says "Where they burn books, they will also burn humans in the end." Powerful.