Opened for less than a week Sydney's newest - and possibly strangest - piece of tourism infrastructure has already become part of the city.
On Tuesday, the first morning of Spring, The Goods Line is bustling. Three toddlers are playing in the vaguely adventurous playground, risking soaking themselves in the fountain.
A few students from the University of Technology, Sydney, are gathered on one of the carpet-sized lawns for a mid-morning latte break.
A group of visiting architects are studying the Frank Gehry-designed Dr Chou Chak Wing Building, better known to Sydneysiders as "the paper bag building".
Sadly, no one as yet is playing table tennis on any of the bright yellow permanent tables dotted along the pedestrian way, but perhaps they will at lunchtime.
It may have cost $15 million to re-imagine this disused, redundant old railway line, but it has undoubtedly added a playful character to a fast-changing precinct that used to be a bleak industrial zone and now is a university, media and museum hub.
The last time members of the public could walk (or cycle) this key corridor between Central Station and Darling Harbour, two of Sydney's tourist landmarks, was 160 years ago.
The first railway in NSW was laid on this route in 1855 to transport goods from the wharves of Darling Harbour to the railway goods yard at Redfern.
Then in 1870, when the Darling Harbour Goods Yard itself was built on the reclaimed mud of Cockle Bay, the line was used to move coal, shale, timber, wheat and wool to and from inland NSW.
Today the entire length of the re-invigorated rail corridor is only 500 metres - basically from the Central Station's Devonshire Tunnel under George Street to the southern boundary of the Powerhouse Museum. Yet this was once of the most lucrative commercial arteries in the British Empire.
A series of signs on the renovated 1879 heritage-listed girder bridge over Ultimo Road bring the history of The Goods Line alive. Working conditions in the goods yard and wharves were among the worst and most dangerous in Australia, helping to give birth to the trades union movement.
However, by the 1960s the writing was on the wall for Sydney as a working port. Increasingly operations moved to Botany Bay - ironically where the First Fleet was originally meant to settle.
Finally the last goods train left Darling Harbour on this line in 1984 (though steam locomotives used the line to get to and from the Powerhouse Museum until recently).
In its new guise, The Goods Line is part playground, part garden and part useful passage way offering new views of the city.
Certainly the award-winning Frank Gehry building is much better seen from The Goods Line than from any other angle.
Of course everyone has likened The Goods Line to New York's famous High Line. Both are reinventions of Industrial Era technology but really that is where the comparison ends.
Yet the unveiling of The Goods Line - the latest in a long line of "rail to trail" projects - has also triggered another thought.
How many cities around the world have beautiful, thought-provoking walks that are only possible because they have used pieces of a previous era's infrastructure?
Here's a start...
Though the first section of the High Line opened in 2009, the third and final section was not unveiled until September 2014. It now runs for almost 2.5 km from the Meatpacking District, through Chelsea to 34th Street near the Javits Convention Center, using an elevated section of the New York Central Railroad called the West Side Line. An estimated five million visitors a year use it.
The High Line on Street View
Sometimes called "the original High Line", the Promenade Plantee was opened in 1993 and follows a high level, abandoned railway line for five km through the 12th arrondissement.
Trains ran on this exquisite viaduct for 110 years until 1969. It is still only a 10 minute walk from Gare-de-Lyons station. Now it offers walkers unforgettable views of Beaux-Arts building, while having encounters with romantic couples and energetic joggers.
Even before railways were invented, the Industrial Revolution began with canals. Lots of cities have them, including Amsterdam, Stockholm and Copenhagen. But London's Regent's Canal takes a lot of beating.
The famous part is the western third, which runs from Little Venice, through Regent's Park (and past London Zoo) to alternative Camden Lock.
But the entire day's walk will take you from Maida Vale to Canary Wharf. Completed in 1820, the canal once carried timber, coal and building materials from one side of London to the other.
The tow path was once, literally, that. A path where strong horses towed the canal barges.
Now it is a recreational jogging track, dog park, walking trail for locals and visitors alike.
Cities once built walls to keep intruders out. Now they exploit them to keep visitors in.
Many cities in every region of the world have city walls worth exploring.
Dubrovnik is arguably the most impressive. The Croatian city is recognised as one of the best-preserved medieval walled cities in the Europe, and a walk around the walls are a perfect way of seeing the UNESCO World Heritage-listed Old Town at its very best.
Some of the highlights include Fort Revelin, Minceta Tower and Lovrijenac Fortress.
Naturally, lots of cities have mountains close by. Honolulu, for example, takes it as an affront if you don't climb Diamond Head while you are there to bask on Waikiki's manicured beaches.
But Hong Kong's Victoria Peak is special. Catch the historic Peak Tram for the 15 minute ride as it makes the 375 metre ascent to the summit of Hong Kong Island. The tram was originally opened in 1888 for the exclusive use of the British Governor and his very wealthy neighbours.
These days it is the starting point for a lovely circular walk which offers unsurpassed views of what remains one of the most spectacular harbours in the world.
OK, perhaps Funchal, capital of Madeira, isn't one of the world's greatest cities.
But when it comes to re-invented infrastructure, it doesn't get much better.
The entire, mountainous island is covered in an intricate matrix of miniature irrigation channels - designed to spread the water evenly, equally and repeatedly.
Of course, that also means the shallow gradients of the levadas are perfect for exploring Madeira by foot.
One of the most unusual reuses of infrastructure for tourism purposes is to be found in York where enthusiastic volunteers are happy to guide you through a history of the latrine - from communal Roman conveniences and Viking toilets to the medieval garderobe (a waterless closet found in castles).
You might want to sit this one out (boom, boom!).
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