The Sydney Opera House was built by two architects, not one, says an historian who is determined to get recognition for the lesser-known Australian architect.
Danish architect Jorn Utzon is widely acclaimed for creating Sydney's most iconic building, but when he controversially resigned and left the country in 1965, Australian architect Peter Hall stepped in and fixed the mess that was left.
But, to this day Mr Utzon is the only architect recognised as the creator of the Opera House, University of Sydney architecture historian and author Anne Watson says.
When Mr Hall took up the job, he was faced with a cascade of issues left by the former architect, including unfinished plans, half-built shells and no interior work leaving him with an "unbuildable concept", she says.
In Ms Watson's book, Poisoned Chalice: Peter Hall and the Sydney Opera House, she details how Mr Hall transformed the original designs into a workable building.
But, she says Mr Utzon isn't to blame for the issues that plagued the opera house for so long.
The architect himself said it was the building that was the problem, and Ms Watson agrees.
She insists it's time for the Australian man who finished the masterpiece to be equally recognised for his contribution to the mammoth project.
And she isn't the only one who thinks so.
Former Australian senator Michael Baume, who wrote the 1967 book The Sydney Opera House Affair, says Ms Watson's book is a belated and proper acknowledgement of Mr Hall's work.
"Until this book, Hall has been disgracefully excluded," he said.
The Sydney Opera House was officially completed in October 1973 - 14 years after construction started.
Mr Hall died 22 years later in 1995 at the age of 64.
