‘Sláinte,” says Dervla Murphy, settling back into her armchair, her pint raised aloft. We are in the bohemian study of her home in the centre of Lismore, County Waterford. Home is actually a collection of unconnected buildings adjoining a cobbled courtyard that once formed the historic town’s marketplace. We are enjoying the great Irish travel writer’s favourite tipple: beer. “Lovely. Lovely,” she says, taking a sip. “Now, off you go.”

She is referring to the start of our interview, I assume, and not peremptorily instructing me to leave – though with Dervla, it seems, you cannot always be sure. She has a reputation for plain speaking, for her no-nonsense approach to life. She dislikes being quizzed by journalists and audiences with her are infrequent.

“Interviewing Dervla is like trying to open an oyster with a wet bus ticket,” her mentor and first publisher, Jock Murray, once said. You get the feeling that over the course of 50-plus years of trailblazing and 26 intrepid travel books, she has got used to quickly gauging the temper of a place, and of people. She gives you a firm handshake, looks you in the eye – and you just hope you pass muster.

“Well, I don’t terribly like that word in relation to my sort of travelling – it’s not anything to do with it,” she says, politely but firmly, in her low-pitched drawl, when I suggest that her pioneering trips must have presented challenges along the way. “Clearly there have been discomforts and extremes of temperature – though not a great deal. But I am not going out to overcome something, like an explorer or serious mountaineer. I am travelling to enjoy myself.”

Murphy, now 86, is being characteristically modest and she similarly dismisses any romantic notion of her being brave or courageous.

“I thank God for my sanguine temperament, which refuses to allow me to believe in disaster until it is finally manifest,” she wrote in Full Tilt, the story of her solo journey by bicycle from Ireland to India in 1963.

“I never cross my bridges till I come to them,” she says. But still, she has crossed many bridges – mostly by cycle or on foot, mostly on her own, and mostly in the more remote and inhospitable parts of the world. She seems to seek out the cut-off and inaccessible, to try to time-travel to a past that to her feels more vital and honest. “Even a brief glimpse of what we were is valuable to help understand what we are,” she writes in Full Tilt.

To that end, Murphy says some of her most memorable experiences have been in Afghanistan, Peru and Siberia, places in which, despite the harshest of environments, she often seems to find intense happiness, even peace. What comes across in the writing is the “sheer bliss” and utter exhilaration that travel can engender in her.

Such was her love for the country, she describes herself as “rabidly and irreparably ‘Afghanatical’” by the end of her time there in 1964. Ancient Herat is “a city of absolute enchantment”, she compares the bounteous Ghorband valley to the Garden of Eden, and is moved by the “incredible, unforgettable beauty” of the mountains of the Hindu Kush.

Her 1,300-mile trek in the high Peruvian Andes in 1977, where few travellers had then ventured, was completed with a pack-mule – and her daughter, Rachel, who was just nine. “People considered it insanity for us to set out with only basic supplies to a part of the country that had no roads, no hospitals, no services,” she says. “But that was why we were there in the first place.”

In 2002, aged 70, she found herself, more by accident than design, in Siberia, where she was captivated by the generosity of the people and the enigmatic landscape, particularly around Lake Baikal and the epic Lena river. “Places such as those have nothing to do with how most people think about Russia, which is centred on Putin and on Moscow,” she says. “There’s a different sort of spell about Siberia.”

If she’s pressed to choose a highlight from her life in travel though, she eventually settles on her three-month trek, in the winter of 1966-67, through the highlands of Ethiopia, with a pack-mule called Jock (named after her publisher).

“That was very, very special,” she says. “Not only was it incredibly beautiful but it also felt ancient and otherworldly, and almost unchanged. For three weeks I was in territory that was so remote that people didn’t even use money.”

She forgets to mention, however, that the hazardous and sometimes hostile journey in Ethiopia was one of a thousand miles on foot, and that she was robbed three times, once by armed bandits who nearly decided to kill her. “That was nasty, and I knew it was very much in the balance,” she says. “I was lucky then. Extremely lucky.”

While Murphy has written that “during a long trek some disaster is inevitable”, you only have to consider the lengthy list of illnesses and injuries she has sustained to realise she has shown remarkable resilience. There has been amoebic dysentery in Pakistan, brucellosis in India, gout and hepatitis in Madagascar, and tick bite fever in South Africa. She fractured her coccyx and broke her foot in Romania, badly injured her knee and ankle in Siberia, and required a new hip after a fall in Palestine.

“The triple tooth abscess in Cameroon was the most painful of all though,” she says, laughing heartily, deeply, and taking another swig of beer. “I thought I was going mad.”

Murphy is a true traveller, the real deal. She hates hotels (“they reek of the nastiest sort of affluence”), prefers “doss houses”, and can sleep anywhere. Just 18 months ago, at the age of 84, she spent the night on the floor at Gatwick airport before a morning flight back to Ireland. The compensations along the way for her, and her readers, have been a prolific series of books that have attempted to show the world from the ground up, from “the ordinary person’s point of view”.

She made an instant impact with her mould-breaking debut, Full Tilt; a book that continues to inspire generations of travellers, and strengthened that success in 1979 with Wheels Within Wheels, the account of her 31 years before she began travelling when she was mostly looking after her invalided mother. “Now that’s what I’d call a real challenge, as major a challenge as you can get, actually.”

Since the 1970s she has moved on to more complex and unstable territories: Northern Ireland at the height of the Troubles; Romania two weeks after the fall of Ceaușescu; the Balkans following the wars in the former Yugoslavia; Rwanda post-genocide; South Africa during the end of apartheid. They are trips that have triggered books she describes as “mongrels”, travelogues that deal with social, historical and political issues, the polemical mixed in with the personal.

Murphy says she read more than 200 books before embarking on her many trips to Israel and the West Bank between 2008 and 2010 – ignores any language barriers, and strives as much as she can “to share people’s way of life”. She is an autodidact, an active listener, curious, fair-minded, good-humoured, wry. “She writes with a kind of combative liberalism,” wrote Ian Jack in the London Review of Books.

She is a woman of strong opinions, too. As well as avoiding hotels, her personal travel bugbears include the arrival of motor roads in remote areas (“and with them all the destructive changes of the modern world”); the obsession with staying in touch via mobile phones and laptops (“these gadgets have led to a negative change in the ethos of travelling”); mass tourism (“I wonder nowadays if travelling, and therefore travel writing, is able to extricate itself from tourism and the tourist industry”); even advanced global capitalism (“there has been a sustained and dreadfully successful campaign to make most people dissatisfied with what I would call the normal life and some would call the simple life”).

If this makes her sound curmudgeonly, travelling has also affirmed many of the values inherited from her unorthodox parents: her mother encouraged cycle trips around Europe, on her own, from the age of 16, in the late 1940s; her bourgeois, county librarian father was jailed for three years in England in 1918 for membership of the IRA. “Something I have learned is that most people are helpful and trustworthy, that people are generally good and corporations and institutions are generally bad.”

Murphy is also a woman of certain unchanging dispositions and routines. An only child, she says she knew she would never marry. Having a “fatherless child”, Rachel, out of wedlock, and on her own in Ireland in the 1960s, didn’t affect her. “I didn’t care what people thought, and again I just got on with it.” She still lives in the town she grew up in. She has never had an agent or accepted an advance for any of her books. She gets up at 5am, has a substantial breakfast of homemade muesli, bread and cheese, sometimes eggs, eats nothing else for the rest of the day and is in bed by 9.30pm.

She has no television (“Yuk! So superficial!”), washing machine, central heating or, of course, mobile phone. She cannot drive. And although she recently invested in a computer – mostly for emails and resolutely kept out of her study – she writes her books in longhand and then on an electric typewriter.

“You can’t process Dervla – she just is what she is,” said Michael Palin in the illuminating 2016 Irish documentary, Who Is Dervla Murphy?

The key to travel, she believes, is to embrace the unpredictable, the unexpected, the unforeseen, “but I feel sad that these sort of experiences are no longer possible – mostly because, and I know I’m just an old fogey, of the mobile phone.” She is also unsure she would be comfortable if one of her three granddaughters was to repeat the trip their mother, Rachel, completed alone when she was 17: a year in India.

“I felt a certain security as a woman travelling alone, and when Rachel went off I was perfectly happy; I hadn’t a care in the world,” she says. “But if one of my granddaughters was to do the same now, I’d be apprehensive in a way I never was. I do think the spread of pornography around the world, especially on the internet, has had a huge effect on men’s behaviour.”

There are other changes close to home, too, with Murphy’s health itself an issue. Always physically stalwart, she has become increasingly stooped, struggles with hepatitis and bronchial problems, has osteoarthritis in her neck and in the last year has developed a heart condition that has rendered her largely immobile: “Can’t cycle. Can’t swim. Can’t walk any distance,” she says, matter-of-factly.

The decline in her health has also affected her first love: writing. She was about halfway through a book on her last journey, to Jordan, “but all this has put a stop to it and I doubt if I’ll ever finish. I’m happy to do shorter pieces, such as reviews and introductions, but you could say I’m reluctantly retired from writing books.”

It’s a sombre note on which to end our conversation but there remains something indefatigable about Dervla Murphy. Despite Jock Murray’s words of caution, she has been warm, open and tremendously good company. Hers is an extraordinary life extremely well lived; she accepts her fate, regrets nothing (“except perhaps not travelling through Tibet before the Chinese took over”) and has no fear of death.

“Well, that’s what happens when the machinery wears out,” she says, downing the last of her second glass of beer. “When you’re old you die. That’s end of story.” And Dervla Murphy lets out that rich and throaty laugh one more time.

• Eleven of Dervla Murphy’s titles are available as Eland Classics at travelbooks.co.uk