The Well of the World Brain was the name of the Senate Building after it was converted to house the World Brain of Yuuzhan'tar.
Shaped like a Yuuzhan Vong skull, the metals of the Building were digested by yorik coral, going deep underground, and providing the Well with an impenetrable wall, capable of surviving concussion missiles and orbital bombardment—possibly even a planetary explosion, allowing the World Brain to survive as a self contained vessel. A hedge maze of ceremonial trees lined the front entrance to the Well. The trees were as resilient as durasteel, and contained toxin filled needles ranging in size from a thumb to a forearm.
During Jacen Solo's sham attempt to sacrifice Ganner Rhysode to the World Brain, Ganner fought off scores of Yuuzhan Vong Warriors, becoming a legend to both the Jeedai heretics and the Warrior caste alike. During the Battle of Yuuzhan'tar, Han Solo, Leia Organa Solo, and the Priest Harrar went to the Well in an attempt to prevent the World Brain from destroying Coruscant.