Foster's 1999 glass dome above the restored Berlin Reichstag — transparency as political symbol.
From Wikipedia
The Reichstag dome is a glass dome constructed on top of the rebuilt Reichstag building in Berlin, Germany. It was designed by architect Norman Foster, from an idea of Gottfried Böhm, and built by Waagner-Biro to symbolize the reunification of Germany. The distinctive appearance of the dome has made it a prominent landmark in the city.