It was in the foothills of the Dolomite mountains that a three-year-old Jannik Sinner took his first steps towards becoming the world's best player.
It started on the ski slopes, where he was so good he later became a giant slalom runner-up in the junior national championships.
Sinner also showed enormous promise on the football pitch with an instinctive ability to play with both feet.
But tennis soon started to take over Sinner's life in the mountain village of Sexten, just a short hike from the Austrian border.
It is a picturesque, peaceful place. Street signs are presented in both Italian and German, but the main language is a German dialect. Plates in restaurants regularly carry meat and dumplings, as if you were ordering from an Austrian or German menu.
It may not look an obvious launchpad for the career of a future world number one - but, as the dome that stretches over a nearby indoor tennis courts proclaims, it is "where champions are born".
Sinner's first coach was family friend Andreas Schönegger. Having given the infant Sinner an introduction to life on skis in his fourth winter, he was entrusted with tennis lessons the following summer.
Sinner was a slight child - often the smallest in his group - but what he lacked in physical presence he more than made up for in talent.
Family friend Andreas Schönegger
"Everybody thinks when they see this guy on the court that to beat him is not a problem, but he had incredible technique from the beginning," Schönegger told BBC Sport.
"The hair was long and red, similar to a girl. The first tournament he played, I remember the group asking me 'Andy, why today plays a girl with us?'
"And I tell them - this is not a girl, it's a very, very strong boy!"
Q&A
Where did Jannik Sinner start his tennis journey?
Jannik Sinner started his tennis journey in the foothills of the Dolomite mountains.
How old was Jannik Sinner when he began playing tennis?
Jannik Sinner was three years old when he began playing tennis.
What significance do the Dolomites have in Jannik Sinner's career?
The Dolomites are significant as they are where Jannik Sinner took his first steps towards becoming a champion.
What is Jannik Sinner known for in tennis?
Jannik Sinner is known for being one of the world's best tennis players.
See every story in News — including breaking news and analysis.
Schönegger has a lot of praise for Sinner's parents. Father Hanspeter - also known as Johann - would sometimes work a 14-hour shift as a chef in the kitchens of a local ski lodge before heading to the courts to practise with his son.
Not that Sinner was ever keen to leave early. Schönegger remembers him as a youngster who stayed on to practise his footwork and groundstrokes after the group lessons were over.
When the time came to decide which sport to devote his abundant talent to, tennis won through – but the decision was not without a personal cost.
At the age of just 13 and a half, Sinner left home, with his destination some 400 miles away.
The renowned Piatti Tennis Centre is also in Italy, but in a town very different to Sexten. Bordighera is on the Italian Riviera, bracketed by the sea, with a beach and an exotic garden referenced by painter Claude Monet.
There is no snow, no skiing, and very little German spoken.
Founder Riccardo Piatti - who had already enjoyed great success with Milos Raonic and Ivan Ljubicic, and worked with a teenage Novak Djokovic - initially thought Sinner was too young for the move.
But Sinner had made up his mind and, with his parents as advocates, Piatti relented.
He decided Sinner should spend every fourth week back in the mountains - reconnecting with family, friends and schoolwork - but his prodigy soon decided he wanted to become a full-time student of the tennis academy.
Sinner admits it was a tough transition. His Italian was limited, his English even more so, and he had very much been a part-time player until that point.
"I never went to the gym before, never played more than a couple of times a week before, and then everything changed," Sinner told me at May's Italian Open.
"I was struggling to get used to the new conditions for my body.
"But it's been an amazing experience and I would do it again, because it makes me grow as a person."
Sinner lived with a Croatian family to give him as normal a life as possible despite being so far from home. He has kept up contact with that family during his rise through the sport's ranks.
Piatti remembers a strong personality and character with a good sense of humour, while coach Andrea Volpini - who travelled with Sinner in his early career - recalls more typical teenage traits.
He remembers a sociable teenager who enjoyed "simple things" like football, ice cream and - when time allowed - a trip to the karting track. Volpini also visited Sinner's hometown with him.
"I went to run with him high in the mountains. It was tough to follow him – he knew all the curves and the jumps, and it was not easy for me," Volpini recalls.
"He spent a lot of time far away and then came back there [to] regenerate, find new energy to restart."
Sinner also differed from many others of his generation in that he never played a junior Grand Slam. Piatti preferred to send him to play on the Futures tour, the lowest rung of men's professional tennis.
"He was, by our opinion, ready to play them - not to win, but these tournaments gave more possibilities for him to work on his goals," Volpini explained.
There were also some handy practice partners from time to time. Roger Federer was a visitor to the academy and on more than one occasion Sinner practised with Djokovic in Monte Carlo.
"The first time you face these great players, maybe more important [are the] off-court moments, when you sit down and take a break," Volpini added.
"We always push Jannik to ask a question. I remember one time in Monte Carlo when Novak told him some advice on his forehand – don't push but try to find a bit shorter corner."
Sinner’s forehand is now one of his biggest weapons and is aided by a superb serve and Djokovic-like movement around the court.
"My idea was that this guy is a player that can beat Novak because they were similar - the movement is very similar," Piatti added.
"The idea was to hit the ball faster than the other one, especially to Djokovic."
Sinner played his first professional tournament in the Egyptian resort of Sharm El Sheikh as a 16-year-old in January 2018. He reached the second round, earning $258 (£192).
"He was very, very skinny. It’s impossible to think in which way it is possible to work because the body was not ready," his former physiotherapist Claudio Zimaglia remembers.
"When he started to work in the gym, it was tough. It is different from going to ski or play soccer for fun."
The work paid off. By the end of the following year, Sinner was already good enough to reach the semi-finals of an ATP Tour event in Antwerp and to win - aged just 18 - the Next Gen ATP Finals that is contested by the best under-21 players of the year.
Piatti could see he had all the ingredients for life at the top.
"95% of his life is tennis. He thinks in tennis," Piatti said.
"He lives his life, but he is thinking always about tennis, in which ways he can do better.
"I think it is part of his character and also part of the people around him."
Sinner split from Piatti after he had reached his second Grand Slam quarter-final at the 2022 Australian Open. He was a top-10 player, and the winner of five ATP Tour titles, but felt the time had come for a fresh perspective.
Under Italy’s Simone Vagnozzi and the Australian Darren Cahill, Sinner has won four Grand Slam titles, risen to the top of the world rankings and developed a potentially era-defining rivalry with Carlos Alcaraz.
But Cahill is quick to point out that the foundations of Sinner's success were laid in those early years.
"I speak about his parents all the time – his grounded upbringing and the way he treats the people around him," Cahill said after Sinner's Wimbledon triumph in 2025.
"He's a good man. He's a good, young fellow. Always has a smile on his face. The person that you see on the tennis court is not the same guy off the court.
"He's a fun-loving guy who is joking around all the time that just loves the company of the people around him."
Sinner’s bid to complete the career Grand Slam of all four major titles at the age of just 24 ran aground at the French Open in May, when a combination of illness, heat and fatigue contributed to a second-round defeat by Juan Manuel Cerundolo.
But when he begins his Wimbledon title defence, the regulars at Bar da Marco in Innichen - the village where Sinner was born - will hope to have more to cheer about.
About 50 square metres of grass was laid down outside the bar for last year's Wimbledon watch parties. Strawberries and white wine were on the menu, and - as has now become customary - one of the empty bottles was annotated and encased in a glass table to commemorate Sinner's latest success.
"We show every match from the quarter-finals onwards to friends and guests," owner Marco Dapoz explained.
"It's always quite full, and you have to check in advance that you can get a seat.
"We drink water to start with and then often champagne or sparkling wine or beer so our guests can celebrate - even when he loses, we celebrate nonetheless."
Innichen, and the neighbouring commune of Sexten where Sinner grew up, are full of images of their favourite son - including of the June day two years ago when he returned for a public celebration of his achievements.
Sinner had just become world number one for the first time, bringing with him the trophy, along with the replica Norman Brookes Challenge Cup he had received for winning his first Grand Slam at the Australian Open that January, and the Davis Cup - which Italy had won for the first time in 47 years the previous November.
The day was organised by mayor Thomas Summerer, who summed up what Sinner means to the region.
"I always say he is incomparable as an athlete when we see everything he has won," Summerer said.
"He speaks very often about his family, about his parents, about his environment - about things very many of us are preoccupied with.
"When he is here, he is always asking after your parents, whether everyone is healthy and then wishes you all the best when he says goodbye.
"In my experience, Jannik the person outstrips Jannik the athlete. It is his simple manner, his sincerity, his openness and his direct connection with people."
Credits
Written by Russell Fuller Subbed by John Skilbeck Edited by Amy Lofthouse Filming by David McDaid and Melissa Sharman Design by Scott McCall Images by Getty, the Piatti Tennis Centre and Andreas Schonegger
Jannik Sinner and Carlos Alcaraz have dominated men’s tennis in 2025. BBC Sport looks at the evolution of their growing rivalry – and where it could go next.
