The Reichstag is the German parliament building located in Berlin that was captured by the Russians during the end of World War II. The Reichstag building was first featured in Call of Duty, then in Call of Duty: World at War, and Call of Duty: World at War (Nintendo DS), and most recently, Call of Duty: WWII.
The Reichstag is featured in the original Call of Duty and Call of Duty: World at War. Both times it appears in the last level of these games. In the Call of Duty mission, "Berlin", the player must fight his way through the Reichstag and then watch as his comrades place the flag on the roof.
In the Call of Duty: World at War mission "Downfall", players also fight through the Reichstag as Dimitri Petrenko. However, this time the entire level takes place within the building. The player must also play a bigger role in the raising of the flag. The player must pick up the flag from the dead flag carrier and plant it on the balcony. Before he does however, the player is shot with a Walther P38 by a lone German soldier and is severely injured. Fortunately, Sgt. Reznov comes to the player's aid and kills the German. The player is then able to plant the flag, while the others claim victory.
The multiplayer map Dome takes place on the top of the Reichstag.