The Sydney Tower is Sydney's tallest structure and the second highest observation tower in the southern hemisphere. The name Sydney Tower has become commonplace in everyday use, however the tower has been known as the Sydney Tower Eye, AMP Tower, Westfield Centrepoint Tower, Centrepoint Tower or simply Centrepoint. The Sydney Tower is a member of the World Federation of Great Towers. The tower is located 309 meters above Sydney's central business district, on Market Street, between Pitt and Castlereagh Street. It is accessible from Pitt Street Mall, Market Street or Castlereagh Street and is located above the Westfield Sydney shopping center (formerly Centrepoint). The tower is open to the public and is one of the most important tourist attractions of the city, being visible from a series of vantage points throughout the city and from the adjacent suburbs. The Sky Tower of Auckland is higher, but the main observation deck of the Tower of Sydney is 50 meters higher than the observation deck on Auckland's Sky Tower. Designed by the Australian architect Donald Crone, the first floors for the Sydney Tower were inaugurated in March 1968. The construction of the office building began in 1970 and the construction of the tower began in 1975. Before the construction of the tower, the height limit in Sydney had been set at 279 meters, to allow safe overflights with flying boats. Public access to the tower began in August 1981. The total cost of construction was 36 million dollars. In 1998, the addition of a lightning rod to the top of the spire extended the total height of the tower to 309 meters, or 327 meters, above sea level. In 2011, Merlin Entertainments acquired the rights to manage the observation deck tower and its name was changed to Sydney Tower Eye. Four sections of the tower are open to the public, three are occupied by Sydney Tower Dining. 360 Bar and Dining, offering sweeping views of the Sydney skyline, is on the first floor of the Sydney Tower. The observation deck, currently called the Sydney Tower Eye, is on the fourth floor of the Sydney Tower. To access this level, visitors can purchase a pass from the operating company or at the gate. The pass allows access to other Sydney attractions, including Wild Life Sydney and the Sydney Aquarium. The Sydney Eye Tower is 250 meters above ground level. It has a fully enclosed observation deck with 360 degree views of the city and surrounding areas. This floor also houses a small gift shop, multilingual touchscreen and a reading that shows data on wind speed, direction, amplitude of the swing and other tower statistics. On September 23, 2011, on the fourth floor of the porch, a 4D cinema was opened, which plays a film with footage of various locations in Sydney. The theater is the first of its kind in Australia; the effects inside the theater include wind, bubbles and fire.