It is a huge, blown-up copy of Lunch atop a Skyscraper, perhaps the most famous image to ever emerge from New York, which depicts 11 men sitting side-by-side on an iron girder nearly 1,000 feet above the Manhattan streets.

It may seem like an odd choice for a boxing gym buried deep inside farm land a few miles north of central London but for Don Charles, the man behind the facility, it was a no-brainer.

“It's just my favourite picture,” says Charles gesturing up towards it. “And when you think about it, it makes a lot of sense for this place.

“These guys are all up there, totally comfortable with what they’re doing but they are all in real danger, one slip and it could all be over for any of them.

“And that’s just like heavyweight boxing.”

That has been Charles' trade for many years, since the early days of Derek Chisora back in Mill Hill all the way to his current position as Daniel Dubois' head trainer. Even Charles' son, George Fox, is a professional heavyweight.

“One day, when all is said and done and everyone is retired,” Charles says. “I want to get all the heavyweights from this era and recreate the picture. Can you imagine them all lined up like that, shooting the breeze.”

Of course the original Lunch Atop a Skyscraper was also actually a staged photograph, which was part of a publicity campaign in 1932 to promote New York's real estate industry a few years into the Great Depression.

While much of what happens around boxing events is staged publicity stunts, the two men fighting at the end of it all are both in very serious danger. As if to labor that point, Queensberry Promotions have billed Saturday’s clash between Dubois and WBO heavyweight champion Fabio Wardley "Don't Blink."

On an adjacent wall to Skyscraper is a long, black-and-white picture of the gym's most successful inhabitant. “Dynamite Daniel Dubois,” it reads. “World Heavyweight Champion.”

He is the challenger against Wardley in Manchester but before defeat to Oleksandr Usyk in July, Dubois had enjoyed the position as IBF world champion. His first and only defense of the belt ended in a memorable knockout of Anthony Joshua at Wembley Stadium, the arch of which you can see from just outside Don’s gym.

It was in the lead up to their September 2024 fight, that Charles decided to build this gym. Before he had thought about any skyscrapers, the picture of Dubois was the first thing he procured.

“I almost broke my neck putting that picture up,” Charles says.

“I remember the first time he came in here was a Monday so on the Sunday night I was in here putting it up so he would see it on his first day. I welcomed him and said ‘this is your gym, this is for your camp.' I was very tearful.”

As Charles speaks, a handful of heavyweights shadowbox in the ring, preparing for an afternoon of hard sparring.

Above them, a rig that Charles bought from an old theater director on Facebook Marketplace holds huge spotlights beaming down onto their backs. The idea is to get his boxers used to boxing “under the lights” so it does not feel new to them on fight night itself.

“This whole gym was built for Daniel,” Charles adds. “I’m not a rich man but I pushed the boat out to do the AJ camp here.

“We normally go to Spain to do camp but because that fight was in September, we could have our camp in British summertime, which is as good as anywhere.

“I’ve known about this land for the last 12 years. I asked the farmer who owns the farm if he minds converting one of the barns into a gym. I said that if we win we will stay — and we won. You can see Wembley from here so it was all meant to be.”

What was not part of the plan, however, was Dubois’ decision to leave Charles and his unique gym behind in the wake of the defeat to Usyk.

The 28-year-old headed east to Essex where he linked up with Tony Sims but he would be back with Don, back where he felt he belonged, just five months later.

“When Daniel left it left a big void because every time I walked in here it didn’t feel the same,” he said of the gym. “The guy I built it for was no longer here.

“So when he left it really hurt me but the way the universe had it is they came back and now it’s business as usual.”

So while the 1932 photograph was always safe, did Charles ever think about taking Dubois down?

“Hell no,” he says instantly. “I would never take that down.

“Nothing was moved because he’s part of the history. Even if he didn’t come back, guess what, he’s part of my history, man. How are you going to erase your history? We just want to make more.”