Not the Reichstag, but the Reich Chancellory. And it wasn’t this memorial but the Soviet memorial and cemetery located at Treptow, located in the former East Berlin. I’ve been to both. Wikipedia has a descriptive article on both memorials.
Incedentally, the Reichstag, though heavily damaged, was not demolished and is currently in use as the seat of Germany’s lower house.
Yes, I confused the two. Thanks.