The A$21.6 billion ($15 billion) Sydney Metro line along a major north-southwest artery has featured in hundreds of photos and videos on TikTok and Instagram since it opened in late August.
In one TikTok video viewed more than 600,000 times, young people dance and celebrate on the train station platform holding Sydney Metro signs.
The excitement is in part a response to how modern the new line, with its driverless trains and bright, spacious stations, feels compared to the aging network in which tens of thousands of commuters pour through every day.
At the heart of the new line is Sydney Central, which got A$955 million overhaul to accommodate the new underground line and elevate the 118-year old station to the level of Kings Cross in London or Grand Central in New York.
"It's not something Sydney has really experienced, it's been a bit overdue," said John Prentice, a principal at architecture and design firm Woods Bagot, who led the design of Sydney Central.
"We wanted to provide Sydney a station on par with stations around the world. It needed to rival those other stations but based on its unique qualities and characteristics."
At Gadigal, a new station next to the pre-World War Two city hub Town Hall, commuters descend to the platform on escalators flanked by six columns weighing 168 tonnes each.
Large murals of train tunnels stand high above commuters at each entrance. The 12.5 metre (14 yard) tall pieces drew inspiration from early Sydney railway tunnels as well those drawn by cartoon character Wile E. Coyote, according to artist Callum Morton.
"You can always tell when something hits," he told Reuters.
"The beauty is on the surface and the sensation you feel in front of it is the most captivating thing... I really wanted to reproduce that feeling."
($1 = 1.4712 Australian dollars)
