John O’Shea goes to bed in a lifejacket. Or so he tells me. “Give a lie 24 hours’ start and the truth will never catch up,” he says. O’Shea owns the house in the Achill Island village of Dooagh that borders the track leading down to what might currently be the most famous 200 metres of sand in all of Ireland, possibly beyond.

A hoarding at the turn-off from the road welcomes visitors to “Achill Island’s Newest Beach!” Below that is a series of quotations from media outlets worldwide: ABC, BBC, Time magazine, Fox News, Shanghai Daily – “Awesome… Amazing… Unbelievable…” But somehow, having driven four and a half hours from Belfast, followed the only main road through the island and clocked the sign for Dooagh (pronounce it as though your next word is Cantona), I drove right past it.

Dooagh, you might say, is almost alphabetically impossible, fitted in as it is between the beaches of Keel and Keem, the latter pronounced “Kim” locally. (The former, for obvious reasons, retains the long vowel.) But it is the physical, or geological, fact of the place that has attracted such global attention. For the beach at Dooagh went missing for three decades, between 1984 and earlier this year, when it reappeared, several thousands tonnes of it, as the story goes, more or less overnight, the result of an exceptional series of spring tide surges.

The rocky shore at Dooagh in 2014. Photograph: Seán Molloy/Achill Tourism

Achill Island is beautiful beyond belief, especially in the July sunshine that I have been lucky enough to hit, but the ocean that surrounds it can be fierce and unforgiving – hence O’Shea’s line about sleeping in a lifejacket. As for his “give a lie a start” line, let’s just say there are conflicting accounts about what really happened to Dooagh beach.

A map hanging in the hallway of the Achill Cliff House Hotel, where I am staying – published in 1988, four years after the great vanishing act – says with a telling lack of drama that the beach “constantly changes its format after winter storms… sometimes a beautiful sandy beach and sometimes rocky and stoney [sic]”.

Marie Kelly, who looks in every day on an elderly neighbour with a house staring straight down the lane to the beach, raises her eyebrows when she talks of the two busloads of Chinese tourists detouring on to Achill after the Shanghai Daily ran its Dooagh “miracle” story. Truth be told, there was always a “smidgen of sand”, she says.

Marie Kelly, who has seen busloads of Chinese tourists on the island since the beach came back. Photograph: Linda Brownlee for the Guardian

All this, I should say, is taking place within five minutes of me pulling into the car park, which, like everything else at Dooagh, is fairly basic, with no path even down to the sand. I have never had to make so little effort (well, if you set aside the drive from Belfast) to find people to talk to.

While I am chatting to Marie and John, a woman approaches and asks John if he ever knew a Mrs Kilbane way back. John says there was a man called Kilbane who drowned with two friends while fishing at night for salmon, and wonders whether she might have been related to him. The woman – her name is Terry Hennessy, Moran as was – says she doesn’t know anything about a drowning. She hasn’t been on Achill since she was “a young one”. “I’m 44 years married, so it must be 50, 51 years,” she says. Then, all she did was dance every night – “and we weren’t even drinking”. She introduces us to her husband, Louis, and daughter Jan. They live in Kildare town, on the opposite side of Ireland, but were in Westport, an hour’s drive away, the previous night for a wedding and, with Dooagh being in the news, thought they would make the journey. Louis has never been on Achill. Jan was here once for an adventure holiday, though possibly a different order of adventure from the one Terry remembers. “The west of Ireland fellas were mad-out.”

Terry Hennessy, who hasn’t been on Achill since she was ‘a young one’. Photograph: Linda Brownlee for the Guardian

Some of them clearly still are, and the women too. About 10 minutes before I arrived, Saoirse McHugh and her boyfriend, Colm (pictured top), nipped down to the beach for a swim – not a stitch on, the pair of them, perhaps encouraged by the fact that Dooagh, for all its newfound fame, or fame regained, is still an underpopulated stretch of sand. It does, it has to be said, face some pretty stiff competition: Achill already has five blue-flag beaches, or one for every 500 of its year-round inhabitants, and only three fewer than the whole of Northern Ireland, with a population 700 times as large. (England, population 30 times that again, has 68.) Marie says she doesn’t know why she is telling me this, putting notions of somewhere more beautiful in my head; but Keem, up over the next hill, is Achill’s Bay of Naples.

A visitor enjoying the sand. Photograph: Linda Brownlee/The Guardian

Mind you, she tells me that the “crowds” of tourists she sees every morning walking down on to Dooagh strand are taking their lives in their hands: this was never a beach where you would have taken your kids. Yet I am looking past her shoulder at several children playing happily in the sand, including the toddler daughter of Linda Brownlee, the photographer, whose family have been coming to this part of Achill for 20 years. Linda’s sister-in-law, whose children are on the beach, is Eileen Ryan, née Kelly – Marie’s niece.

“We always swam here,” Eileen says, “and surfed.” (“Eileen is a lifeguard,” Marie says. “Used to be,” Eileen says. “You don’t stop,” says Marie.) Eileen’s husband, Mick, remembers noticing more sand at Dooagh around about the St Patrick’s weekend. When I tell him I’m still finding it hard to imagine that thousands of tonnes of sand could be thrown up, just like that, he takes me up to the rocky part of the beach and shows me a couple of broken slabs of concrete with rusted metal poles sticking out of them. Those were bicycle stands, he says, dislodged from the car park in the last really big storm three or four years ago, when there were waves in gardens 30ft back from where we are standing. Don’t underestimate the power of the sea, in other words. All the same, he thinks there may have been “a whole load of balloons” sent up about the miraculous return: an opportunity seized on to generate much-needed publicity.

Eileen and Mick Ryan’s son Sean. Photograph: Linda Brownlee for the Guardian

In the 1960s and 70s, even into the 80s, Achill was the place to be, Diarmuid Gielty tells me, but then people started going farther afield, to Spain and suchlike, places where they were guaranteed decent weather. A native of Achill, Diarmuid had been living in Dublin, but returned to the island 12 years ago to open a shop in Dooagh. “I grew up in a pub back the road,” he tells me, “so I knew what hard work was.”

The first eight years were grand, the next two worse than dreadful, and eventually he had to put the shop up for sale and go back to what he had been doing in Dublin – quantity surveying – with a company in Westport, although he was fortunate in being able to work from home. More people would come back, he thinks, if there were reliable broadband throughout the island.

I ask about the large number of new houses I saw as I drove into Dooagh. They’re mostly empty, he says, pointing to a hill behind us. “Go up there at night and look down, and see how many lights you see on.” The Dooagh beach story has stirred memories for a few people. “It can’t do any harm,” Diarmuid says, even if it has come too late for him and his shop.

Diarmuid Gielty’s daughter Muireann. Photograph: Linda Brownlee/The Guardian

Diarmuid’s brother, Alan, now runs the family pub, Gielty’s Clew Bay bar and restaurant – “the most westerly bar in Ireland” (and presumably on the European continental shelf), a short distance from the beach. He has definitely noticed an upturn in trade since the spring. The beach is “drawing people down through the island”, he says. People such as Andrew and Christine Gibbons, who are “spinning out for the day” from Toormakeady, a further half-hour beyond Westport. It is their 23rd wedding anniversary and they seem content to look at the beach, leaning on the bonnet of their car, and take a selfie with the sea – and the sand, of course, in the background. I ask if they think they might stick around for dinner. They don’t know. “We might just keep on spinning,” Christine says.

Eileen and Mick Ryan’s daughter Aoibheann. Photograph: Linda Brownlee for the Guardian

A little later, Annette Daly, who lives in Dublin, arrives with her sons, aged 15, 13 and 10, and unfolds a canvas chair to one side of the car park. It’s a couple of years since she was in Achill, and she has come down to the beach today to stop the boys going stir-crazy, because although it’s a glorious afternoon now, yesterday was dire – “the sky was on the ground”, in Alan Gielty’s words. Annette loves the west: there is something so energising about the Atlantic Ocean, but it’s a case of heaven or hell, depending on the day. I noticed that many of the older, stone houses, in ruins now, are built side-on to the sea – protection from the weather taking priority over the spectacular view in former times.

Annette Daly’s sons on the beach. Photograph: Linda Brownlee for the Guardian

Annette has another theory about Dooagh beach, which was “just rocks” last time she was here. Rather than the tidal surges depositing a whole lot of new sand, she thinks they stripped away the stones that had covered it all these years. As she is telling me this, I remember the couple I saw earlier – late middle-age – who pulled up in their Offaly-registration car and helped themselves to a couple of large stones, whether as souvenirs or as rockery infill. Doing their little bit to ensure the sand’s survival.

Much later, as the sun is getting round to thinking about going down (we are very far west: the sun is in no great hurry), I spot another couple walking in the shallows arm in arm, him with his trousers rolled up and his shoes in his hands. When they arrive back at the car park, I ask them whether they have come here specially to see the beach. No, the man says, they live on Achill. They have walked this beach many a time.

Even when it was stony?

“Even when it was stony.”

You must prefer it now that it’s sandy.

“It’s easier on the feet, all right.”

Michael Gielty, who remembers the old beach. Photograph: Linda Brownlee for the Guardian

And what if the tides were to surge again next winter and take away those thousands of tonnes of sand?

“Well, the sound of the waves on the stones was nice, too,” he replies evenly.

I have been on Achill only a day, but already I share some of his equanimity. Whatever the “format”, the beach at Dooagh adds more than a few grains’ – or pebbles’ – worth to the store of happiness and beauty in the world.

As to what exactly happened here earlier this year, I leave the last word to Michael Gielty, father of Diarmuid and Alan, who knows the beaches of Achill better than most. Now in his mid-80s, Michael was once a shark fisherman, spending five days of every week, April to June, spearing the basking sharks that swam into Keem bay – “always left to right” – to de-lice their skin on the rocks close to shore. Michael tells me it was a couple of days before word of Dooagh beach’s reappearance reached him. He came straight down and stood on the rocks, looking at the sand. “I never thought I would see it again.” And wonder like that – I can hear it even in the retelling – you just can’t fake.