Racehorses running down the streets at iconic global locations such as Sydney Harbour Bridge or Fifth Avenue in New York...
It might sound implausible, but the man spearheading the project has told BBC Sport he hopes agreements for the first such race meetings, on a special artificial surface, will be in place by the end of next month.
He is Peter Phillips, the Queen's eldest grandson, and here he outlines details of racing, safety, crowd and betting plans for the 'City Racing' project and how racing's best-known supporter is following the idea...
What is this all about?
Phillips, who is 14th in line to the throne, has been working on the proposals for five years since staging an equestrian event on a similar surface on Horse Guards Parade in London.
He says that leg of the Global Champions Tour demonstrated how safe 'pop-up' conditions for horses in a competitive environment could be installed and removed within three days.
Working with the same company - a specialist in providing racetracks that also helped stage equestrian events and beach volleyball at the 2012 London Olympics - a successful trial was held at Aintree racecourse in November 2018.
The ambitious aim is to stage fixtures which have six flat races, with eight runners each over a five-furlong (1,000m) straight course in some of the world's most famous cities with the best international jockeys competing before thousands of spectators.
"We are now in the process of talking to a number of cities about hosting races later in 2019 and 2020," said Phillips.
"We are hoping to have some of these agreements in place by the end of March.
"There will be a pedestrian crowd barrier, two or three metres back from the edge of the track and people lined four or five deep, getting up close to these horses running at 30mph. That's going to create a unique energy and buzz."
His sports promotion company SEL UK is in partnership with leading racecourse owners the Jockey Club, equine surface manufacturers Andrews Bowen, PR company JSC Sport and investment firms New World Capital Advisors and RHT.
What about safety?
A special synthetic surface would be laid on the streets, topped with a thick layer of sand and able to easily withstand the weight of thoroughbreds racing at speed.
It was trialled with three demonstration races on a road through the centre of Aintree racecourse, home of the Grand National.
"The surface has been rigorously tested and the feedback from jockeys and trainers has been positive," said Phillips, 41.
"We are dealing with horses, who are athletes and injuries happen, but we have to make sure we put all the checks and balances in place.
"Equine safety is paramount. We have a veterinary advisory board and a gold-standard welfare framework."
He said the track, surface, sub-layer and railings would all require sanctioning from the British Horseracing Authority.
Paul Fisher, chief executive of the Jockey Club - which owns racecourses including Aintree, Cheltenham, Newmarket and Kempton Park - believes the concept could help bring racing to "a younger, urban audience".
"I'm a keen cricket fan and this could be racing's Twenty20. It could take it to a whole new audience around the world," said Fisher.
Where might racing take place?
London and Paris remain on the wishlist, and while talks with those venues have stalled for now over logistics, the short-term options include Australia, Asia, the Middle East and the United States.
Complex negotiations are needed with the local city and racing authorities, but Collins Street in Melbourne and Singapore's Orchard Road are understood to be potential locations.
New York, Sydney, Macau and Las Vegas are among others being considered.
"It has to be a full day out, with entertainment outside of the track and post-meeting entertainment. It will be up to the local provider to decide what they want to put on," said Phillips.
Examples might be a food fair or music festival in the area, with the schedule timed to coincide with a major existing racing fixture
It is hoped tens of thousands of people would attend each event, with eight renowned jockeys, plus reserves, lined up to ride locally-based horses in the races.
The races would be 'handicaps' involving horses rated 0-90 - so the horses would not be at the top level, but they would need to fit criteria around their suitability.
Jockeys would accumulate points based on their finishing positions, and the rider with the highest total would be the event winner.
"The focus is on the jockeys. It should act as a platform for the racing industry to promote itself to a wider audience who may not go to traditional racetracks," said Phillips.
"A lot of it is ensuring we work within the existing race calendars of the communities we are going to. There are certain times of year they will have a concentration of horses or jockeys."
Racing is likely to take place sometime between September and April, largely outside of the core British flat racing turf season. Meetings could be during the day or under lights, depending on the locality.
"We are not competitors to the tracks - we are one race meeting in the course of a season," said Phillips.
What has the reaction been like?
This is not the only new innovation proposed in horse racing, with backers of 'The Series' already having agreements in place with eight courses in England, Scotland and the Republic of Ireland for their plans.
That separate project is based on a Formula 1-style format, with branded teams at Thursday evening meetings in the summer.
Both projects have been met with some scepticism about whether they will actually go ahead. So what are the realistic hopes for City Racing?
"I'm an optimist, but also a pessimist and cautious about trumpeting something before it gets off the ground," said Phillips.
"I would say the likelihood of a City Racing event is more 70-30 than 50-50 and I am probably being conservative with that.
"In a 12-month period, we might start with two or three events and build from there. Hopefully within five years, we would have six to eight meetings annually."
Funding would come from sponsors, ticketing and hospitality, with betting available on all the races.
"It might be that 50% of people say this is really cool, and it will be fantastic, and the other 50% are more cautious," added Phillips.
So what does the Queen make of it all?
Phillips is the son of the Princess Royal and brother to Zara Tindall - both winners of the BBC Sports Personality of the Year award in the past for their equestrian exploits.
His grandmother, the Queen, is a racehorse owner and breeder, and he has spoken to the monarch about the project.
"That is one of those conversations where I can't divulge a huge amount, although she is following it with interest," said Phillips.
"Every time I see her, she always asks about how it's going and what the latest updates are."