Sydney Tower is Sydney’s tallest structure and the second tallest observation tower in the Southern Hemisphere. The name Sydney Tower has become common in daily usage; however, the tower has been known as the Sydney Tower Eye, AMP Tower, Flower Tower, Glower Tower, Westfield Centrepoint Tower, Big Poke, Centrepoint Tower or just Centrepoint. The Sydney Tower is a member of the World Federation of Great Towers.The tower stands 309 m above the Sydney central business district , located on Market Street, between Pitt and Castlereagh Streets. It is accessible from the Pitt Street Mall, Market Street or Castlereagh Street and sits above the Westfield Sydney shopping centre. The tower is open to the public, and is one of the most prominent tourist attractions in the city, being visible from a number of vantage points throughout town and from adjoining suburbs. Auckland’s Sky Tower is taller but Sydney Tower’s main observation deck is almost 30 m higher than the observation deck on Auckland’s Sky Tower. While the shopping centre at the base of the tower is run by the Westfield Group, the tower itself is occupied by Trippas White Group, which owns and operates Sydney Tower Dining, and Merlin Entertainments, which owns and operates the "Sydney Tower Eye" observation deck and "Oztrek" simulated ride attraction.

More details: https://en.wikipedia.org/wiki/Sydney_Tower