Chatting about his Aberdeen Angus cattle and black Welsh mountain sheep, he looks for all the world like the lean, all-weather west country farmer that - technically - he is.
He also happens to be the world’s greatest living explorer, an authentic larger-than-life figure who casually mentions in passing how he cut off the fingers of his left hand with a hacksaw after developing frostbite, and ran seven marathons in seven days only weeks after emergency heart surgery.
But at the moment, Sir Ranulph Twisleton-Wykeham-Fiennes is more interested in talking about the sheep on his remote Exmoor farm. Press him on why, eight years beyond pensionable age, he continues to subject himself to ordeals beyond human imagination and the question seems to take him by surprise.
“Why not?” he asks. “Of course it’s getting harder, but so long as I remember to take my pills I seem to be ok.”
Categorising the 73-year-old third Baronet of Banbury, who prefers to be called Ran, takes eight pages on Wikipedia. Take your pick from: swashbuckling explorer, best-selling author of 35 books, renegade army officer, farmer, charity fund-raiser and legendary after-dinner speaker.
After Eton, his army career in the Royal Scots Greys and the Special Air Service was enlivened by unleashing a pig covered in grease among top brass at an army ball and blowing up a concrete dam which he decided had spoiled a pretty village. He was fined and dismissed from the SAS but ater forgiven.
He claims he was seriously considered for the role of James Bond but lost out to Roger Moore. Apparently his hands were too big. Expect the unexpected from Sir Ran and you won’t be disappointed.
Now after dozens of boys’ book adventures, he’s once again risking his life in what he regards as his greatest test in 50 years of doing what doubters have said couldn’t be done.
His current Global Reach Challenge involves becoming the first person in the world to cross both polar ice caps and to climb the highest mountain on every continent - what he hopes will be the triumphant culmination of a lifetime of exploration and death-defying challenges.
It’s an extension of what Sir Ran calls “The Big One” - reaching the north and south Poles in 1982 and becoming the first pensioner to climb Everest, which he did at his third attempt in 2009.
The new challenge started so well. He has already crossed both polar ice-caps, climbed Mount Ectica, Mount Kilimanjaro in Africa and Mount Elbrus in Russia. Then just hours from the top of Mount Aconcagua in South America, back pain forced him to abandon the attempt and he was airlifted off the mountain.
Soon he hopes to be ready to tackle Mount Kosciuszko, Australia’s highest peak, before returning to have another go at Aconcagua. Then there’s just Mount Denali in North America to crack to complete the challenge and claim a world first. Sir Ran has no doubt that he’ll do it.
“I was very disappointed to have to leave Aconcagua,” he says. “But experience has told me that not every challenge will be a success - it took me three attempts to climb Everest.
I now have a good report from the doctor and I am determined to keep going. I just hope that my back behaves itself.”
It will be his second attempt on Mount Denali - back problems forced him to abandon the first. “I’m more than ready to have another go,” he says. “It’s a real challenge - climbers only had an 18 per cent success rate last year, and I’ve never rated myself as a mountaineer!”
What helps drive on this extraordinary man is raising money for charity, particularly the Marie Curie cancer foundation - for which the current challenge has already raised over £350,000 - in memory of his first wife Ginny, who died of stomach cancer in 2004. “Marie Curie were wonderful to her,” he says. “I will never forget that.” Like all Sir Ran’s challenges, this one was planned on the remote Exmoor farm he shares with his second wife Louise and their daughter Elizabeth.
He found the farm 30 years ago. “It had been empty for years and had no electricity or water supply. The roof leaked and the floors were rotten but Ginny just knew it was the place for us and she was right.”
It’s a place where he fiercely guards his privacy. No photographs are allowed and we had to promise not to reveal the location. The 200 acres of farmland are the trainingground for numerous expeditions and where he selects potential team members.
“You can go for 15 miles across the moor without seeing anyone or anything and it’s the ideal place to put people through their paces. I like to run there for at least an hour a day and more if I can.”
In fact, despite suffering constant accidents and health problems, Sir Ran shows little sign of slowing down and nothing is allowed to get in the way of a challenge After all, he’s the polar explorer who dislikes the cold, the mountaineer who sufferers from a fear of heights, vertigo and serious breathing problems, and the athlete who has had major heart-attacks and cancer.
After suffering a heart attack at Bristol Airport it took 13 attempts to restart his heart, but he was running marathons only weeks later.
After deciding to retire from mountaineering in 2009, Sir Ran changed his mind last year on hearing there were plans to extend “The Big One” to include a mountain on every continent.
He told us: “The goalposts have been moved. If I had known that when I climbed Everest I would have continued on to the other five mountains. Now I’ve got to go ahead and finish the job. Luckily I have Everest under my belt, plus Mount Kilimanjaro and Mount Elbrus, the highest in Europe, which I have previously climbed.
“Apparently there are five other people who want to take up the challenge, but I can’t worry about that.”
A lifetime of exploration began in 1967 after eight years in the army. An early adventure was travelling up the White Nile on a hovercraft. Since then Sir Ran has led more than 30 expeditions and raised an astonishing £20 million for charity.
Numerous epic journeys have followed, including 3,000 miles through the Northwest Passage in an open boat, the first unsupported trek across the Antarctic and the Transglobe expedition around the world on its polar axis.
Sir Ran told us that he started raising money for charity after a conversation with his patron, Prince Charles, who is supporting the current challenge.
“He asked who we were raising money for and when I said ‘No-one sir, it’s not part of breaking world records’, he replied: ‘Oh dear. I can’t carry on being a patron if you don’t’. Not surprisingly we’ve always worked for charity since then!”
Sir Ran is always on the lookout for new challenges. “There’s a lot more competition nowadays,” he said. “It’s not like it was 30 or 40 years ago when we were pioneering these things. Today practically everybody’s grandmother is up Everest every weekend.
“The challenges that are left are incredibly difficult. Not that it will stop me trying to do them.”
To donate to the Marie Curie charity, go to justgiving.com/ranulph