On the narrow footpath down to Porthcurno beach, I am conscious of adding to the gridlock. Overcrowding on the Cornish coast has been making the news this week, and as I stop to talk to husband and wife Aiden Fisher, 59, and Lesley Whatley, 60, holidaymakers troop past, laden with backpacks, bodyboards and tote bags stuffed with towels and plastic spades.

“I’ve been coming here since I was a child,” says Fisher, his feet sinking into the sand as he holds his walking boots. “It does seem busier now – and more international, too.”

Down on the sand, I speak to a French couple “on a tour of Cornwall”, who survey the cliff path up to the Minack amphitheatre, while a Spanish family play football nearby. Making her way down the rocks, Michelle Wu, 42, from Surrey, is visiting with her sister’s family who have come all the way from Beijing. “Cornwall was one of the places they really wanted to go,” she says.

The number of visitors to Cornwall – and the cars and motorhomes they travel in – have been swelling for some time, fuelled in part by the hit BBC show Poldark, which is filmed on location at Porthcurno beach and Kynance Cove, as well as social media posts depicting the beauty of Cornwall’s elegant bays. Instagram, in particular, has been responsible for driving contemporary travel trends; this summer, Pedn Vounder, a small beach neighbouring Porthcurno, was overrun with visitors after photographs of its crystal blue water and white sand went viral, prompting comments such as “Cornwall’s Caribbean”.

Poldark alone, according to the tourist board, is responsible for a 10% increase in visitors to the region this summer. But the heatwave has created a perfect storm, causing an estimated 20% spike in tourists on top of the 4.5 million who already visit each year. Cue road blocks, parking issues, campsites unable to receive deliveries – and even the regional ambulance service saying at times it has “struggled” to reach patients. From websites directing people to fake Cornish beaches to the banning of second home owners for new properties in St Ives, it is an issue of growing concern for residents. To top it all, this week the local tourist board said it had stopped promoting the two Poldark beaches in brochures and campaigns due to overcrowding.

“Nobody wants to see this sort of mass tourism affecting the area, affecting the tourist experience and clogging the roads,” Malcolm Bell, Visit Cornwall’s chief executive, told the BBC, adding that he wants to see a “redistribution” of tourism across the county. Cornwall has 400 beaches along its coastline, he pointed out, many of which would benefit from an increase in visitors. “This is a sustainability issue,” he said.

Outside Porthcurno’s beach cafe, I find Katy Bevan, 54, eager for a tea break after walking the coastal path. She has seen the reports about overcrowding on the news. “It’s to do with that Poldark show, isn’t it?” she says, quick to point out that Poldark was not why she and her husband decided to visit. “It must be really hard for the villagers. Mousehole, where we’re staying, is all rental cottages. I hope the locals are able to capitalise on it – it must be hard to maintain a community with all the strangers in your town.”

In the village pub, The Cable Station Inn, the landlord, Mick Wilby, 67, warily dismisses the issue. “It’s a load of hype,” he says. “Obviously it needs something done, perhaps another park-and-ride car park, but we’re only talking six to eight weeks a year tops – come September, it’s a better pace.”

The issue might evaporate come winter, but, with the UK tourism industry growing significantly, it will be only a matter of months before it returns. According to the World Travel and Tourism Council, the UK travel and tourism sector grew more than four times faster than the UK economy in 2017, with domestic travel growing by 5.8% year on year. As one tourism expert put it to me: “It’s a recession-proof industry.”

We have become used to debating the fallout of tourism in destinations such as Venice, which this spring tested segregation measures for tourists and locals at locations such as the Rialto and San Marco, and the visibly simmering tensions in Barcelona, where Airbnb apartments have been blamed for a rise in rent prices and stag and hen dos have been testing the patience of residents (in both these destinations, locals have taken to the streets to protest about how tourism is being managed). But it is also becoming harder to ignore locations closer to home. Beyond Cornwall, Edinburgh, Bath, Oxford and Cambridge are all grappling with the challenge of booming visitor numbers to their historic centres.

At the opposite end of the country to Cornwall, the Isle of Skye is facing a similar predicament: a rural destination with limited infrastructure that in a short space of time has seen a huge surge in visitors. Last summer residents called for “urgent help” after Skye became a must-visit spot following its use as a location for a number of films and music videos, along with a raised profile on social media.

“In Cornwall, it’s social media driving people to two beaches in Poldark,” says Alistair Danter, project manager at destination management organisation Skye Connect. “In Skye, it’s social media driving people to five iconic destinations to take a selfie.”

Again, it’s an issue of tourist distribution. According to Danter, visitor numbers in Skye increased by 13-14% between 2014-17, but the number of visitors going to the Fairy Pools – one of the island’s iconic spots – did so by 54%. “For the people living in these locations, life in the past two years has become challenging,” he says, pointing to a frustrating problem with tourist behaviour, in which visitors want to tick off “must-see” spots. “In the corresponding period, other scenic locations actually saw a drop in numbers.”

He adds: “The frustration on Skye is that people think that’s all there is to see. Talk to your B&B host and they’ll tell you some off-the-beaten-track locations where you’ll be on your own except for, if you’re lucky, an eagle.”

Skye, like Cornwall, mainly consists of single-track roads and limited parking spaces. Danter admits the island will take a few years to resolve its infrastructure pressures, although it is working hard to do so. Also, similar to the west country region, it is economically dependent on tourism. Visitors to Skye generate £110m each year and 25% of the population is directly employed by tourism. In Cornwall, overnight visits from UK travellers contribute more than £1bn to its economy each year, with an extra £128m from international visits. According to the ONS, tourism contributes more to the economy of the region than any other part of the country.

“We need people to move on from the tick-box culture we live in,” says Danter. “Visitors should pause a moment, plan their visit, and they’ll have a much better experience.”

For Patricia Yates, the director of strategy and communications at VisitBritain, it is about finding a balance: “I would see the rise of social and digital media as an opportunity that we could be harnessing,” she says, explaining that VisitBritain uses Instagram photographers to help promote destinations, something that is now common in the travel industry. (Iceland is a good example of a destination whose popularity has exploded due to the photo-sharing app.) “But I think there is work to be done on telling the narrative about places. Of course there’s an opportunity for social media to suddenly take off, which can be incredibly positive – for example, one fish restaurant in Brighton became hugely popular after a Chinese celebrity did a post about it – but sometimes the popularity can be overwhelming.”

In the university towns of Oxford and Cambridge there have been reports of local disdain for the surge in tourism. Oxford had around 7 million visitors in 2016, while Cambridge saw visitor numbers jump by 2 million between 2013 and 2016. “Short-stay tourism numbers are on a trajectory that threatens to overwhelm the city within a very few years,” councillor John Hipkin told Cambridgeshire Live last December. “This is a matter of the utmost urgency and trotting out official statements about the ‘value to the city of tourism’ is not good enough. We need firm and decisive action to deal with the imminent threat.” As with Skye, strategies in these cities involve encouraging visitors to stay longer (meaning they will actually spend some money during their trip) and visit further afield.

Edinburgh, the top UK tourist destination after London, is also facing up to the challenges tourism can bring, particularly during its intense summer festival season. A report released in January by the city council – Managing Our Festival City – described how problems of overcrowding were affecting daily life for residents, and suggested the need for a complete overhaul of the city centre. The city council has also been campaigning to introduce a “tourist tax” of around £1-2 per night per bedroom on hotels and home rentals such as Airbnb. This is a model already used in European cities such as Barcelona, Berlin and Venice and, although it is pending approval from the Scottish government, it seems likely to be introduced. This year, Bath, which has around a million overnight visitors each year, also renewed lobbying of the government to introduce a similar tax.

Justin Francis, the CEO of Responsible Travel, a company that strives to encourage tourism that benefits local communities, says this is an issue the UK could have seen coming for decades. He believes what has changed in the past two years is that residents have finally been saying “enough”. Francis is supportive of a tourist tax, and argues that more should be done to manage growth, something that has become more of a challenge with the advent of home-sharing sites such as Airbnb. Previously, to extend a hotel, or build a new one, permission would need to be granted; Airbnb has caused accommodation to rocket in unregulated destinations.

“This hasn’t just happened,” he says. “Broadly speaking, tourism globally has been unmanaged and never been taken seriously by government. It’s fun, everybody’s happy, right? But really, tourism is one of the biggest and in some cases most aggressive industries on earth and it is taking governments a very long time to recognise that it needs managing.”

He adds: “It’s not just big destinations with millions of tourists – in a small village, it can just take 50 tourists to be too much. We really need to use our imagination a bit more. We’re all obsessed with the top 10 list on Tripadvisor, we’re obsessed with Instagram and getting the photo everyone else is sharing, and we’re losing the spirit of adventure of discovering places on our own.”

In the case of Cornwall, however, he says it’s important to recognise the economic need. “It’s one of the poorest counties in England,” he says. “And the second-poorest region in northern Europe. One quarter of children live in poverty. So Cornwall desperately needs tourists. It’s also the county that’s most dependent on tourism in England as a part of its total revenue.”

Back in Porthcurno, where open-top buses ferry in snap-happy visitors and a black-and-white flag of Cornwall flutters on the roadside as you enter the village, this seems to be the bottom line. The owner of my B&B points out that her house is one of only 25 residences in the village: “Without the tourists, there wouldn’t be anyone here,” she explains.

Publican Wilby has a similar position. “Every year you pray for a good summer,” he says. “You gotta generate enough money in the summer to pay the bills in winter. Sun’s out means a good season, and this has been a fantastic season.”