On the morning of the Sydney Harbour Bridge's official opening on March 19, 1932, controversy struck.
Just minutes before the ceremony, Francis de Groot, a right-wing extremist, emerged from the crowd on horseback and slashed the ribbon with a sword.
He was tackled to the ground by police and removed from the scene.
The annual Sydney Harbour New Year's Eve fireworks display - with the bridge as its centrepiece - began in 1976.
The performance has grown to become what many people regard as the world's leading celebration to usher in the New Year.
Construction of the Sydney Harbour Bridge began in 1923 and took eight years to complete.
During that period 1400 workers were employed and 16 people died.
The Sydney Harbour Bridge's four towering concrete pylons are purely decorative.
Today the 89-metre high structures contain a museum, tourist information office and a traffic monitoring centre.
There were plans to blow up the Sydney Harbour Bridge during World War II.
Fearing a Japanese invasion in 1942 US General Douglas MacArthur, (pictured far left) who was based in Australia commanding allied forces drew up plans for its destruction if the enemy reached Sydney.
It is the world's largest steel arch bridge, spanning 504m across Sydney Harbour and standing 134m high.
It is also one of the world's top -en longest spanning arch bridges.
Controversy about who was responsible for the Sydney Harbour Bridge's successful design has brewed since it opened in 1932.
Australians credit engineer John Bradfield, pictured, who oversaw the design and construction of bridge.
But just after its opening, English engineer Ralph Freeman, who managed the project through to completion, claimed he had been overlooked.
In 2000, thousands of people marched across the Sydney Harbour Bridge to demand reconciliation for Indigenous Australians.
The iconic structure has become a popular venue for protests and demonstrations, both legal and illegal.
Comedian Paul Hogan worked on the Sydney Harbour Bridge as a rigger.
Hogan began the gruelling job on the bridge in the 1970s and continued in it for about 10 years finding fame on Australian television.
(Russell McPhredan)
The Sydney Harbour Bridge is constantly being painted to keep it looking fresh and protect the structure from the elements
The structure is so large that by the time the painters they have finished, it's time to start the job again.
Former RAAF pilot Peter Isaacson flew a Lancaster bomber under the Sydney Harbour Bridge during World War II.
The decorated pilot flouted regulations by taking the huge aircraft under the bridge in 1943. But it was reported at the time that the stunt helped raised war loans.
The photo of Mr Isaacson was taken in 2006.
(Paul Rovere/The Age)
The eight-year construction of the Sydney Harbour Bridge involved six million hand-driven rivets to put the structure together.
After they were fixed, the job was completed with 272,000 litres of paint.
There have been a variety of vehicles that have crossed the Sydney Harbour Bridge in its 90-year history.
But the fastest was probably by former Australian Formula 1 driver Mark Webber who drove his grand prix car across the bridge in 2005.
(Photo: Louise Douvis)
Most of the steel used to build the Sydney Harbour Bridge came from the other side of the world.
About 80 per cent of the steel required to build the 53,000-tonne structure was imported from the UK.
Since 1998, thrill seekers have been able to climb the Sydney Harbour Bridge up to the peak of its arch.
More than three million people have made the trek to the top to enjoy fabulous views of Sydney and the harbour.
The Sydney Harbour Bridge is a popular wedding venue, with its stunning location.
And since 2008, couples have been able to tie the knot by climbing to the top.
The Sydney Harbour Bridge has attracted daredevils since it was opened 90 years ago.
In 1973, French tightrope walker Philippe Petit walked between the pylons at the northern end. (Photo: John O'Gready)