(CNN) The $145 million redevelopment of the iconic Longchamp Racecourse is entering its final phase, with building work set to be completed this December.
The Paris venue has hosted the Prix de l'Arc de Triomphe -- known as the world's richest race on turf -- since the days of Napoleon III over 150 years ago.
And now, having closed to the public following Golden Horn's breathtaking victory in 2015, it is on track for a grand reopening on April 8, 2018.
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"There are millions of tourists every year in Paris and we must take them to the racecourse," says Olivier Delloye, director general of governing body France Galop.
"It can be seen as a rather bold move when the industry is facing many challenges -- like the new competition from sports betting -- but still any company has to invest in their future.
"It was clear that our flagship course could be redeveloped to maintain its standard and compare well to all the major racecourses in the world."
While Longchamp previously featured two stands capable of holding 7,000 people each, the new design centers on a single 10,000-seater grandstand.
Though overall it can still accommodate as many as 60,000 on big race days, comfort and sustainability have been prioritized over sheer size.
"The former Longchamp was very big and dominated by concrete," says Delloye. "This racecourse will be much greener than the old one. We have multiplied the green surfaces by three compared to before and we have also increased the number of trees by 20 percent.
"It will really be a green bubble for Parisians, just 10 minutes from L'Arc De Triomphe."
Paris' Longchamp racecourse hosts one of the world's most famous horse races -- the Prix de l'Arc de Triomphe. The site currently houses two huge grandstands -- side by side -- built in the 1960s. This computer-generated image (and the ones which follow) show how the new design will transform the site when completed.
The new design which will replace the old stands is the work of Dominique Perrault. The Paris-based architect has designed iconic structures all over the world and was awarded the Praemium Imperiale -- an annual prize awarded by the Japanese Art Association.
Click here to see more of his work.
The existing grandstands at Longchamp are packed in the first weekend of October for the running of the Prix de l'Arc de Triomphe -- the richest flat race on turf in the world.
But for the remainder of the year, the stands remain largely empty -- around 30 race meetings are held annually at Longchamp, attracting just a few thousand spectators each time.
Perrault's new design includes just one grandstand but will be "transparent," he says, affording views both east and west.
"The building has two faces -- one in front of the race and one behind," he says.
"On each plateau you have some services -- clubs, hospitality space, restaurants -- but you can see in all directions," Perrault explains.
"The horse-racing side looks out to the east onto Paris, the Eiffel Tower. To the west, you have the River Seine and very nice landscape, a park."
"The idea is you walk on a different plateau and the view on either side is uninterrupted -- like a fluid promenade," he says.
Some of the building's architectural details will also echo its natural surroundings.
"We have a lot of references to the nature around," Perrault said.
"We designed a handrail with a pattern print like a part of the forest. Also we developed some points in the concrete where we printed the scenes of the wood in the 19th century."
Perrault's design was chosen from a shortlist of six. The renovation plan was agreed by France Galop -- the country's horse racing governing body -- in 2011, but funding issues and doubts over Longchamp's viability as a year-round race venue have delayed construction until now.
The project has an estimated cost of €130 million ($145m), Perrault says. Building work is set to get underway after this year's "Arc" and is scheduled to be completed in 2017.
In 2016, the historic race will be held at Chantilly, 50 kilometers north of Paris.
Of all the familiar features of Longchamps -- from the weighing room to the parade ring -- the only thing that has remained is the track itself.
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"I'm sure it will look great," Delloye enthuses, looking ahead to next year's L'Arc De Triomphe. "We have so many people really waiting to be back at Longchamp for the Arc.
"That doesn't mean it doesn't work at Chantilly -- the last two years have been great -- but still, Longchamp is Longchamp."