5. Sky Tower (Auckland)
The 328 metre sky tower is the tallest structure of the southern hemisphere.
It's an observation and telecommunications tower located on the corner of Victoria and Federal Streets in the Auckland CBD, Auckland City, New Zealand.
It took 2000 tonnes of reinforcing steel, 660 tonnes of structural steel and 15,000 cubic metres of concrete to erect it.
It can withstand 200km/h winds, earthquakes up to eight on the Richter scale and on a clear day, visibility is around 82km.
The highest indoor point is Sky Deck, which has seamless glass giving unimpeded 360º views.
