The Opera House was supposed to take 4 years and cost $7 million — it took 14 years and cost $102 million. The shells were impossible to build as originally designed; it took 6 years for engineers to discover they could be constructed from sections of a single sphere. Utzon resigned in 1966, never returned to see his masterpiece, and refused all payment. The roof tiles are self-cleaning — 1,056,006 ceramic tiles made in Sweden, glazed in two colours (creamy white and matte white), arranged in a chevron pattern that required no two to be cut the same way.

At 134 metres high and 503 metres long, the bridge's arch is made of 52,800 tons of steel. During the Great Depression, 1,400 workers spent 8 years riveting 6 million hand-driven rivets into place — 16 men died during construction. At the opening ceremony in 1932, a lone horseman rode up to the ribbon and slashed it with his sword, declaring it open "in the name of the decent and respectable people of Australia" — a protest that became part of the bridge's mythology.

The Queen Victoria Building was originally designed as a marketplace for fruit, vegetables, and fish — yet it was built with a grand dome, stained glass windows, and a concert hall. Construction cost 112 cars of sandstone and nearly bankrupted the city council. By the 1950s, it had become a rundown government office building slated for demolition. The Lord Mayor, Leo Port, fought to save it, and the restoration cost four times more than the original construction. Today the building contains two unique clocks: the King's Clock and the Royal Clock, which re-enact different scenes from British history on the hour.

The Art Gallery's original Victorian wing was built in 1885, then extended in 1969 with a Neoclassical addition, and finally in 2021 with a contemporary glass pavilion — creating a single building that documents 136 years of Australian architectural taste. The gallery holds the world's largest collection of Australian art, including works from Indigenous artists whose ancestors lived on that land for 60,000 years before the gallery was built. The original building was paid for by public subscription, with citizens donating whatever they could afford.

Cadman's Cottage is the second oldest building in Sydney and the oldest surviving residential building in Australia. It was built just 28 years after the First Fleet arrived, making it a direct link to the convict era. The cottage originally sat directly on the water's edge of Sydney Cove — but 200 years of landfill have pushed the shoreline 100 metres away, leaving the cottage stranded inland. It survived because it was used as a sailing office and police station for over a century, protecting it from the demolition that cleared most of colonial Sydney.

St Mary's Cathedral took 132 years to complete — the original 1865 building burned down, then reconstruction spanned two centuries. The twin spires were only finished in 2000 using original 19th-century plans discovered in the cathedral archives. The cathedral is built entirely from local Sydney sandstone, quarried within sight of the building site. As the largest cathedral in Australia, its construction spanned the horse-and-cart era to the internet age.