Known the world over, this Australian masterpiece is considered one of the 20th century's most iconic buildings. It was designed by Danish architect Jørn Utzon, who won the Opera House international design competition in 1957 and the work was headed up by an Australian architectural team. This UNESCO World Heritage-listed building came in over budget – costing AU$102 million (£52.9m) – as well as 10 years behind schedule, but since its royal opening in 1973 it's delighted design fans around the world.

A one hundred-metre sky garden and more amazing Australian architecture