The new dome of the Reichstag (the seat of the German parliament, Berlin) was completed in 1999 after reconstruction by British architect Norman Foster.
It is made of glass, contains a mirrored cone that directs sunlight into the building, has an open top with a funnel beneath to collect rain water, and has a spiral walkway that visitors can walk on to admire the architecture and the views over Berlin.
The glass, that lets visitors take a look at the inside of the parliament chamber, symbolizes the transparency of the German democracy.
The Reichstag building was originally built in 1894 to house the Parliament. It was used until 1933 when, on the night of February 27th, it was set on fire. The arson, allegedly started by communist Marinus van der Lubbe, was used by Hitler and the Nazi government as an excuse to persecute Communists for suspected revolution and to suspend civil rights in a so called effort to protect the German people. It is widely believed that the Nazis started the fire themselves to hasten the course of events that let them rid the country of all political opponents and establish themselves into power. What happened afterwards is well known. ..
The building was reconstructed in the 1960s and the 1990s.
The dome can be visited for free after registering on the official website of the Bundestag. A very informative audio guide is provided for free. A guided tour can also be booked.