The Atrium of the Senate was the main public hall of the Senate Building. At one end stood the Great Door of the Senate, and the other led to the Grand Convocation Chamber. It was lined with statues of the greatest heroes and politicians of the Galactic Republic.
When the Yuuzhan Vong captured Coruscant during their invasion of the Galaxy, the Senate Building was shaped into the Well of the World Brain, as part of the process of transforming the galactic capital into a new Yuuzhan'tar. The Atrium remained in use as the main entranceway of the building, with the walls, floors and ceilings sheathed in a layer of yorik coral.
Shortly after the World Brain's installation, much of the Atrium was destroyed during Ganner Rhysode's epic battle with the Yuuzhan Vong. However, the damage seemed to have been disguised by the time of the Battle of Yuuzhan'tar a little over a year later.
After the liberation of Coruscant, the Atrium was restored to its former self and was used once more as the main hall of the Senate.