For years it was one of the centers of social life at the CBA. The vestibule, known as Fuentecilla because of the fountain-shaped finial on the dome of the Ballroom, served as the entrance area to the President's Room, the Board Room, and the Games Room.

This room is not rented individually. It will be associated with the use of the entire floor, functioning as a support or extension of the Hall of Columns.