Ah, holidays... the joy of sun, sea and social media, if my recent break is anything to go by. At the start of July, my husband and I travelled to Santorini for four days. Famed for its stunning sunsets, whitewashed clifftop villages and blue-domed churches, we knew it wasn't exactly an off-the-beaten-track destination. But it would be a relaxing one, we imagined, with good food and wine, and even better hotels - all our boxes ticked.
It's a popular checklist. Last year, an estimated 2 million visitors (not counting another 18,000 who come ashore daily from huge cruise liners) landed on the Greek island, which, at just 30 square miles, is home to 20,000 full-time residents.
Unfortunately for Santorini, however, it feels as if 1.5 million of them are visiting purely to take faux-spontaneous photos of themselves. The statistics bear this out: the Greek islands are among the world's top 10 destinations to post on Instagram - up there with Marrakesh, Tulum in Mexico, Amsterdam, Positano and Bali.
And so, rather than unwinding - away from the pressures of modern life - we found ourselves trapped on an island full of Instagrammers, intent on spoiling all that is sacred about the summer holiday in the pursuit of social media "likes".
Laying by our hotel pool was akin to being extras on a photo shoot. We were forced to watch - pictures obviously only being snapped in envy-inducing prime spots, such as the edge of a clifftop infinity pool - as women queued to get in front of the friend or partner they'd corralled into being their photographer.
Things took on a familiarity which was as depressing as it was unintentionally hilarious: swimsuit legs were hoiked up, then pulled down and images checked to see which looked better. Photos were taken with hats on and off, staring out to sea in fake contemplation, gazing at the camera, pretending to find something (nothing) hilarious, looking over a shoulder, in the water, sitting on the edge of the water with a drink in hand - before changing one's swimsuit, adding more make-up and starting again. Then it was time for the friend to repeat the same agonising process. It was all so contrived and self-conscious, not to mention an extraordinary amount of effort.
Forget beach bags, the Instagram crowd are taking full-on camera bags to the pool. Wannabe-influencers appear to travel with collapsible reflectors to create better lighting, tripods and pocket Osmo cameras for taking high-quality video. Someone even had a laptop on her sunlounger to edit the photos there and then. One fellow guest was told not to swim behind an American woman having her 110th photo taken, as it "disrupted the light on the water".
For the first day, I can't deny, I was enthralled by people displaying their vanity so openly. In the days of film cameras (God, I sound ancient - I'm 40), it was potluck whether your pictures came out at all, let alone if you looked half decent. Even if you did manage to get one you loved, only a handful of people would ever see it.
Santorini wasn't like this the last time I visited, 10 years ago. Of course, it was still heaving - tourists have flocked here for decades. And it would be churlish to suggest many weren't taking multiple selfies on digital cameras in the Noughties, too. But they weren't subjecting everyone around them to a relentless public quest for validation.
The problem is magnified in the iconic caldera-view villages of Oia and Imerovigli, where residents have erected signs asking people not to use drones and reminding them that, "This is our home". But with 5.5 million Instagram posts tagged to the island, and counting, they have their work cut out. Others have reported seeing similar pleas elsewhere, with farmers in the lavender fields of Provence resorting to putting up banners reading "Please respect our work" to deter the selfie-tourists (it did not).
Then there are the Instagrammers who risk life and limb for likes - a recent example being the hordes who have flocked to pose at a beautiful, turquoise lake in the Spanish coastal region of Carballo, only to later learn that it is actually a toxic dump; the azure waters the result of a Second World War-era tungsten mine. One Instagram influencer told Spanish news outlet that she had suffered vomiting and a rash for two weeks after bathing in the "Galician Chernobyl".
Look, I use Instagram. My problem isn't with the platform itself. It is the fact that - as men's editor of Conde Nast Traveller, David Annand, puts it: "We've turned the camera around, focusing not out, but in. Photography no longer encourages seeing; it simply encourages projecting, turning the world's great vistas into mere backdrops for the self."
And when so many people visit the same place to take a picture of the same church, the same cobbled street, the same infinity pool... are they really experiencing it?
To be honest, I wouldn't care if it didn't affect other people's experiences. Witness the crowds blindly walking (some even jogging along a narrow clifftop hiking path with no barriers), holding their phones in front of their faces, angrily colliding with whoever dares to get in their way.
At a candlelit restaurant, my husband and I looked around the dozen tables hosting our fellow diners to find all but two occupied by couples with both their faces lit up by their phones as they scrolled, mindlessly, looking at other people's lives. So much for enjoying the moment.
A friend who lives in Florence described watching an endless stream of people lining up to take photos sat on the wall of the Ponte Vecchio. "I frequently see people stopping others from taking pictures or asking people to move so they can get an image just so," he says. "People have always taken pictures, but not hundreds spending 15 minutes in the one spot. It's not about the view, it's about them".
Beautiful places like this, and Santorini, are victims of their own success - something that hasn't escaped the notice of mayor Nikos Zorzos, who last year claimed to be concerned about the tourism on his island. But it doesn't seem to be a concern for those selling the dream - caldera-view rooms on the island can cost several thousand pounds per night. We saw acrylic Instagram plinths in hotel receptions asking guests to take pictures and upload them, using the hotel's hashtag and offering a charging point should they - horror of horrors! - run out of battery.
Our taxi driver told us Instagram was the best thing that had happened in decades. "The last time we got so much free publicity was the Amorgos earthquake of 1956, which made Santorini international news for a bad reason," he said. "This is a way of us showing our beauty and redressing the balance."
There is no doubt Instagram is a powerful marketing tool - according to travel company Topdeck, 18 per cent of 18-30-year-olds book holidays directly based on posts.
But how many would go back to somewhere they've already 'grammed? And how many of us - having spent several days dodging narcissists taking photographs of themselves - would return?
My husband thinks he has the solution: "Next time, darling," he says, "we'll just go to Hull in January."
The Telegraph, London