What is the "Amber Room" in the novel, The Amber Room?

In 1701, Frederick I of Prussia commissioned panels of amber at his Charlottenburg palace or the Catherine Palace. He thought an amber filler room would be beautiful. The room was only partially completed in 1712, when the kingship passed on to Frederick William I who declared the room would not be finished and packed up the panels. In 1755, Empress Elizabeth of Prussia decided to put the panels on display. The room was finally finished by 1770. When Hitler learned of the panels, he instructed Erich Koch to return the room to Konigsberg. The Nazis opened their own museum and claimed it was a part of German history. In 1945, the beginning of the end for the Nazis, Koch ordered that the panels be taken away and Alfred Rohde supervised their removal. The panels were lost after the war.