This architectural masterpiece is one of the most iconic buildings in Australia, and is visited by more than 10.9 million people each year. As all things good, it took more than three times the expected time to build it, from 4 to 14 years. Even more alarmingly, the cost for building it was 14 times larger than expected, from $7 to $102 million. 

The end result, however, is so beautiful that it was added to UNESCO's World Heritage in 2007. Interestingly, the cooling system uses seawater taken directly from the harbor nearby, how cool is that?!

Photo by Kristin Poinar