The iconic building on Sydney Harbour, Sydney Opera House, has joined other famous world structures such as India's Taj Mahal and the Great Wall of China when it was inscribed a World Heritage Building by the United Nations Education, Scientific and Cultural Organisation's World Heritage Committee on June 28, 2007.

Sydney Opera House was described by the UNESCO committee as a "daring and visionary experiment that has had an enduring influence on the emergent architecture of the late 20th-century. The building is a great artistic monument and an icon."

The Opera Theatre, seating 1,547, is mainly used for performances of opera, ballet and dance. The auditorium, like the Concert Hall, is paneled in wood for acoustic reasons, but the ceiling and walls are painted black to allow the audience to focus its attention upon the stage. The proscenium opening is 12 metres (38 feet) wide and 7 metres (24 feet) high and the stage extends back 25 metres (82 feet). Built into the stage floor is a revolve 14 metres (46 feet) in diameter and there are four platform lifts 10.5 by 3.5 metres (35 by 12 feet) which raise and lower the scenery between the set storage area at ground level and the stage 10 metres (33 feet) above. The orchestra pit can accommodate up to 75 musicians.
The Drama Theatre accommodates performances of drama and dance. It seats 544. This auditorium, like the Opera Theatre, is black but the rather low ceiling is made of refrigerated aluminum panels which help to create an even temperature without a draught. The stage, which is about 15 metres (52 feet) square, contains two revolves, one inside the other, which can turn separately or together. The stage curtain, also designed by John Coburn, is similar to that in the Opera Theatre but is woven in dark colours. It is known as the Curtain of the Moon.
The largest hall is the Concert Hall, which seats 2,679. It is used for a wide variety of performances including symphony concerts, chamber music, opera, dance, choral concerts, pop, jazz and folk concerts, variety shows and conventions.
Seating 398, the Playhouse is used for small cast plays, lectures and seminars. It is also a fully equipped cinema. Originally designed for chamber music as well, the Playhouse is paneled with the white birch plywood.

The Opera House was built as a performance venue and includes a concert hall, opera and drama theatres, a playhouse and studio. In the years since its opening by Queen Elizabeth II on 20 October 1973, it has provided a fitting showcase for some of the world’s most renowned artists including Ella Fitzgerald, Yehudi Menuhin, Miriam Makeba, kd lang, Billy Connolly, Kiri Te Kanawa, John Williams, Bryn Terfel, Mel Gibson, Dame Joan Sutherland, Philip Glass, Luciano Pavarotti, Sydney Symphony Orchestra, the Australian Chamber Orchestra, Bangarra Dance Theatre and the Academy of St Martin's-in-the-Field.

Beyond providing this function, it is a building with its own sense of drama – a structure, surrounded by the changing moods and activities of the harbour, that make it a performance in itself. Utzon has explained that the two ideas which inspired his Opera House design were firstly, the organic forms of nature, and secondly, the desire to create sensory experiences to bring pleasure to the building's patrons. He used shapes and materials in an unprecedented way to make this happen. The white Swedish tiles covering the shells give the Opera House its own vitality and moods. Professor of Architecture at Cardiff University, Richard Weston, described them as 'some of the most alive surfaces in architecture, by turn flaring with diamonds of light; sheer dazzling white in full sun, pearlescent…in shadow; or glowing cream, pink or ochre as they return the ambient light'.

Designed at the vast scale of the harbour itself, its low edges contain enough visual appeal for human interest. More remarkable is that the scheme makes no reference to history or to classical architectural forms. The roof is more important than the walls, consequently the language of walls - columns, divisions, windows and pediments - has been effectively dispensed with. As a public building, it conceals its usage in its lack of historical associations, and restores the concept of the ‘monument’ as being acceptable in social terms.

The Sydney Opera House also embodies timeless popular metaphors. The building’s organic shape and lack of surface decoration have made it both timeless and ageless. Moreover, it demonstrates how buildings can add to environmental experience rather than detract from it - something of spiritual value independent of function.

The building and the setting look orchestrated, and the synergy between the setting and the building make it appear that the scheme actually involved flooding the harbour valley to set the building off to best advantage.

Despite so much richness, the building has had virtually no influence on the shape and form of Australian buildings which followed. It remains something of an enigma which crowns the silent collapse of Western Classical architecture from being the one language for great public buildings.

Internally, the building becomes a performance of a different type, with a Sydney music critic observing after the opening concert that the chamber had resonated 'as if the hall itself were a large cello'.

The Sydney Opera House is the creative expression of an architect's vision, a government's will, engineering doggedness and public hopes. Above all, it is now a vibrant entity in the Australian psyche - a reflection of what this nation is, and what it aspires to be.

About the Building

There are nearly 1000 rooms in the Opera House including the five main auditoria. There is also a Reception Hall, five rehearsal studios, four restaurants, six theatre bars, extensive foyer and lounge areas, sixty dressing rooms and suites, library, an artists' lounge and canteen known as the "Green Room", administrative offices and extensive plant and machinery areas.

The building covers about 1.8 hectares (4.5 acres) of its 2.2 hectare (5.5 acre) site. It has about 4.5 hectares (11 acres) of usable floor space.

It is approximately 185 m (611 ft) long and 120m (380 ft) wide at its widest point. The highest roof vault (above the Concert Hall) is 67m (221 ft) above sea level.

The roofs are made up of 2,194 pre-cast concrete sections. These sections weigh up to 15.5 tonnes (15 tons) each. They are held together by 350 km (217 miles) of tensioned steel cable. The roofs weigh 27,230 tonnes and are covered with exactly 1,056,056 Swedish ceramic tiles arranged in 4,253 pre-cast lids.

The entire building weighs 161,000 tonnes. It is supported on 580 concrete piers sunk up to 25 m (82 ft) below sea level. The roofs are supported on 32 concrete columns up to 2.5 m (8 ft) square.

The exterior and interior walls, stairs and floors are faced with pink aggregate granite which was quarried at Tarana in New South Wales. The two woods used extensively to decorate the interiors are brush box and white birch plywood which were both cut in northern NSW.

There are 6,225 sq m (67,000 sq ft) of glass, made in France, in the mouths of the roofs and other areas of the building. It is in two layers - one plain and the other demi-topaz tinted. About 2,000 panes in 700 sizes were installed.

There are 645 km (400 miles) of electrical cable. The power supply, equivalent to the needs of a town of 25,000 people, is regulated by 120 distribution boards. Twenty six air-conditioning plant rooms move more than 28,500 cubic metres (1,000,000 cubic feet) of air per minute through 19.5 km (12 miles) of ducting.