1. The architect Jorn Utzon was initially rejected by three judges in a 1956 competition to design the Sydney Opera House, but his entry was picked out by the fourth judge, renowned American architect Eero Saarinen, who declared it outstanding. Mr Utzon beat 232 other entrants.
2. He won £5,000 for his design.
3. Mr Utzon had never visited the site of the Sydney Opera House before entering the design competition, but used his naval experience to study charts of the harbour
Workers install lights on the 185 metres long, 120 metres wide Sydney Opera House
4. Work started on it in 1959, with 10,000 builders employed.
5. Mr Utzon resigned as chief architect of the Opera House in February 1966, after a new Liberal government was elected and the Minister of Works stopped payments to him. There were protests in the streets, demanding that Utzon be reinstated, but he left Australia in April of the same year, and never returned to see his design take shape.
6. The Sydney Opera House Trust took up communicating with Mr Utzon again in the late Nineties, and the architect was appointed as a design consultant for future works.
7. When Queen Elizabeth II opened the Sydney Opera House on October 20, 1973, Utzon was awarded the Gold Medal of the Royal Institute of Architects Australia – but was absent from the ceremony.
8. The Sydney Opera House’s construction cost $AUS 102 million (£60 million) – the original estimated cost was $AUS 7 million (£4.1 million).
9. The Opera House’s sails were built using cranes made specifically for the job in France, each costing $AUS 100,000 (£59,000)
10. The building is 185 metres long and 120 metres wide.
11. The highest roof point is 67 metres above sea-level – the same as a 22-storey high building
12. Its roof is made of 2,194 pre-cast concrete sections.
13. These sections weigh up to 15 tons each…
14. …and are held together by 350km of tensioned steel cable…
15. …which if laid end-to-end would reach Canberra
16. The roof is covered with more than one million tiles, made by Swedish company Höganas.
17. The building has 6,225 square metres of glass and 645 kilometres of electric cable.
18. The glass used in the building is unique to the Sydney Opera House, and was made to order in France.
19. The architectural style is Expressionist Modernism – which involves innovative form and use of novel materials.
20. The entire site covers an area of 5.798 hectares. Eight Boeing 747s could sit wing-to-wing on the site.
21. The House hosts 3,000 events every year.
22. Two hundred thousand people per year take a guided tour of the building.
23. Its performances have an annual audience of two million.
24. The largest of the seven venues, the Concert Hall, has 2,679 seats.
25. The smallest is the Utzon room, which seats up to 210 people.
26. The Concert Hall’s Grand Organ is the largest mechanical version of this instrument in the world, with 10,154 pipes. It took ten years to build.
27. Total rooms? 1,000.
28. 15,500 lightbulbs are changed every year at the Opera House.
29. The 40th anniversary is being celebrated with a month-long calendar of events throughout October, including a large concert on 27th October with performances by the Sydney Symphony Orchestra, Opera Australia and Sydney Philharmonia Choirs.
The Sydeny Opera House was a focal point during the Summer 2000 Olympics
30. You won’t go hungry or thirsty at the Sydney Opera House: it has three restaurants, a café, an espresso bar, and opera and theatre bars.
31. The building was listed as a UNESCO World Heritage site in 2007, and the organisation describes it as “great urban sculpture set in a remarkable waterscape, at the tip of a peninsula projecting into Sydney Harbour.”
32. Arnold Schwarzenegger won his final Mr Olympia body building title in the Concert Hall in 1980.
33. During the Eighties, a net was put in place above the orchestra pit in the Opera Theatre, after a live chicken walked off the stage during a performance of Boris Godunov and landed on a cellist.
34. The Sydney Opera House was the setting for Jon Cleary’s crime novel Helga’s Web, in which a body is found in the building’s basement. The book was made into a film starring, Scobie Malone, in 1975.
35. The building is open to the public 363 days a year, closing only on Christmas Day and Good Friday. But staff work 24/7, 365 days of the year.
36. The first person to perform at the Sydney Opera House was Paul Robeson – in 1960, he sang Ol’ Man River to the construction workers as they ate lunch.
37. The first opera performed at the house was Sergei Prokofiev’s War and Peace, on September 28 1973.
38. The House was originally a popular film-screening venue, with a particular surfing movie theme.
39. The venue served as the focus for triathlon events during the 2000 Summer Olympics.
40. Since opening the Opera House, the Queen has visited four times