Panteón de Agripa
The centre of City Hall features an auditorium, based on the Pantheon, Rome, and several smaller reception rooms. The auditorium is a large circular hall that can seat up to 1,600 people and is covered by the largest copper dome in the southern hemisphere. Beneath this dome there are 8,500 L.E.D lights that display a light show. When originally built it was intended that the building would house most of the Council's administrative offices, Aldermen's (councillors') offices, the Council Chamber, a public library and several reception rooms, in addition to the auditorium. As the role of local government increased in the 1950s and 1960s, the reception rooms, hallways and side entrance vestibules (in Adelaide and Ann Streets) were converted to office space. Additional offices were constructed on the roof and in the basement.