OPERA HOUSE
Australia's best-known building, with its unique sail-like profile on Sydney Harbour, is familiar around the world.  Opened by the Queen in 1973, it contains a 2690-seat main hall, 1547-seat secondary auditorium, a drama theatre, recording hall, music room, recital room and a 10,000-pipe organ which cost more than $1 million.  The white room gleams from a million Swedish tiles and weighs 157,800 tonnes.

The building's serene appearance belies the turbulence of its birth.  Danish architect Joern Utzon resigned half-way through the project in the midst of a turmoil of building delays, ballooning costs  (from $7-million to an eventual $10.2-million), personality clashes, political power plays and departmental pressures.  Despite its name, opera is staged in the lesser hall.

ROYAL BOTANIC GARDENS
The nation's first public gardens began as a farm planted out with seeds and plants collected at Rio de Janeiro and the Cape of Good Hope by the First Fleet. 

Some beds still existing evolved from those early gardening patches.  The 29 hectares on the shores of Sydney Harbour are laid out in the Upper Garden, Middle Garden, Lower Garden and Garden Palace Grounds, and more than two million visitors a year stroll through the landscaped grounds, which are also a favourite route for battalions of lunchtime joggers.

Four thousand trees and plants represent most parts of the world, and more than a million specimens are to be seen in the new $4.5-million herbarium.  There is also an excellent palm collection.  The adjacent Domain covers 51ha of less formal parkland and on Sunday draws listeners to its Speakers' Corner.

Among the statues are figures of Henry Lawson, Robert Burns, Governor Phillip, Prince Albert and five-times Premier Sir John Robertson.

Under an obelisk are the ashes of explorer and botanist Allan Cunningham, who resigned as Colonial Botanist when he discovered the staff were expected to grow vegetables for high officials.

ST ANDREW'S ANGLICAN CATHEDRAL
A pedestrian precinct has opened up the view of Australia's oldest cathedral and it can no be fully enjoyed.  Although perhaps modest by expected cathedral standards, its mellow stone complements the Gothic Lines.

Governor Macquarie laid the first foundation stone of Greenway's ambitious design in 1819, but the building was postponed because of financial strictures and it was another three decades before work resumed, this time to a new Edmund Blacket design.  The two towers were added in the 1870's.

ST MARY'S CATHOLIC CATHEDRAL
The authoritative Gothic church is almost surrounded by parkland.  One of the best views is from the east;  this outlook, up a hill, puts the building on the skyline.  The building is the third on the site, the foundation stone being laid in 1868.  Building continued until 1928, but after more than half a century it is still without the twin spires planned in the original design.

The cathedral has some fine windows and at the entrance are statues of Archbishop Michael Kelly, who finished the building, and his predecessor, Archbishop Kelly.

Catholics have worshipped on this ground for more than 160 years.  Their spiritual needs were ignored in the early years of colonialism - being forced to attend Protestant services - but in 1821 Macquarie Church of the Blessed Virgin Mary  (Only three years earlier he had deported a priest).  The early church gave way to the first St Mary's Cathedral, which was destroyed by fire in 1865.

THE AUSTRALIAN MUSEUM
Eight million items are in the collections, which concentrate on natural science, anthropology and ethnology.  There is also an outstanding stamp collection.

The first wing of the museum was opened in 1849, and extensions have gone on ever since.  For 20 years before the first premises were habitable, exhibits were housed in the homes of the Judge-Advocate and Chief Justice, and Darlinghurst court house.