Parliament House, Canberra, Australia. The building was designed by Mitchell/Giurgola Architects and opened on 9 May 1988 by Elizabeth II. At the time of the construction, it was the most expensive building in the world at more than A$1.1 billion.
It contains 4,700 rooms and many areas are open to the public. The main foyer contains a marble staircase and leads to the Great Hall.