It is truly one of the world's most iconic buildings. Instantly recognisable, inspiring affection and attention in equal measure.
Its own history reflecting its times - then and now.
The original Bennelong gave the first concert on the site of the Sydney Opera House for Governor Phillip and his party in 1791.
Governor Macquarie then ordered a fort here to protect the new colony, which was replaced - in less volatile times - by a tram depot.
In 1956 Premier Cahill's competition to create 'an opera house' attracted hundreds of entries from 32 countries, setting no design parameters, or a cost limit.
The 38 year old Danish architect's design was a masterpiece,creating new rules for architecture worldwide.
There were to be theatres side by side on a large podium, with a shell-shaped roof
The decision to build it was bold, visionary and unexpected, but nearly crushed by the politics that followed.
Funding was put under pressure, and the budget ballooneed to 1,500 per cent over.
But even as the vitriol flowed, the work progressed, brick by brick, tile by revolutionary tile.
Utzon's concept for the roof shells was designed with renowned engineers Ove Arup - the final shape derived from the surface of a single imagined sphere.
Cut into an orange, the effect can be recreated.
Baulderstone Hornibrook - which also built parts of the harbor tunnel built the roof shells - and much of the interior.
Utzon's creation required technology which was only then being invented; demanding construction skills that noone was totally sure the nation - or any nation- possessed.
With a breathtakingly epic - and almost poetic - vision of a young nation seeking a place in the world.
Yet Jorn Utzon wasn't there to see it.
Drained by a change of government, constant questioning, professional controversy, and popular criticism, he went home, never to return.
It has to be one of the lesser moments in our history.
Architect Harry Seidler even led street protests - demanding Mr. Utzon be re-engaged.
Utzon's Opera House cost $102 million; it's value today is closer to $ 1.6 Billion.
That's nearly half a billion more than the Empire State Building in New York; but now it needs another investment, for the next half century
Outside Australia- this national icon defines us as much as the kangaroo.
At home, it's been the the focus of occasional protests, annual joy - a national image on which our history can be projected.
Or a place to just wonder.
In 1999, Jorn Utzon was delighted to be re-engaged to create new design principles, as a guide for any future changes to the building.
But he was, his family ruefully admitted, too old now to travel. Too far to touch his creation for the first time.
When he died there were tears for what he'd done, and for what he left behind.
And what it said about all of us.
With the flags on the harbor bridge at half mast, fluttering over his work of genius, sharing Bennelong's legacy on the peninsula below.
It stands by itself as one of the indisputable masterpieces of human creativity
Not only in the 20th century, but in the history of humankind
