Image copyright Getty Images Image caption Venetians have long complained of the big ships, and they are not alone 
 
 There are places where the surge of global tourism is starting to feel like a tidal wave. 
 
 Ancient cities around the shores of the Mediterranean and Adriatic are on the front line, their stone streets squeezed full of summer visitors as budget airlines and giant cruise ships unload ever-growing armies of tourists. 
 
 Take the Croatian city of Dubrovnik: a perfectly preserved historical miniature, carved from honey-coloured stone set in a sea of postcard blue. 
 
 Around 1,500 people live within the walls of its Old City, custodians of cultural treasures left by everyone from the Romans and the Ostrogoths to the Venetians and the Habsburgs. 
 
 Tourist takeover 
 
 On a busy day three modern cruise ships, each one the size of a floating apartment building, can disgorge five or six times that number of people into the city. 
 
 Image copyright Getty Images Image caption Dubrovnik's allure for tourists has been amplified by Game of Thrones 
 
 They join the throngs of tourists staying in local hotels and in rooms rented over the internet, in streets where almost every elegant stone house has been converted into a B&B. 
 
 The overall effect is Disneylandish - a sense that you meet no-one but other tourists or ice-cream sellers, tour guides, waiters, reception clerks and buskers who are there to keep the tourist wheels turning. 
 
 Mark Thomas, who edits The Dubrovnik Times, explains the phenomenon like this. "When I first got here, I'd stand back if I saw that people were taking photographs of each other. Now there are so many people that I know if I did that, I'd never get anywhere here." 
 
 'Winter is coming' 
 
 Dubrovnik has a particular problem because its ancient appeal has now been bolstered by that most modern of phenomena - the HBO mini-series. The city, unchanged for centuries, provides the main locations for Game of Thrones. 
 
 Fans come on pilgrimages to visit the settings. One souvenir shop owner, who told me he doesn't watch the series himself, admitted he had Googled a couple of catchphrases to help attract customers. 
 
 "It does seem crazy," he admitted, "to stand here when it's 35 degrees, shouting that 'Winter is Coming'." 
 
 Image copyright Città di Capri Image caption The idyllic Italian island of Capri is buckling under the thousands of daily tourists 
 
 Dubrovnik is not alone in struggling to balance its need for tourists' money with the need to ensure that those tourists don't end up destroying the beauty they've come to see. 
 
 The tiny Italian island of Capri has warned that it could "explode" under the pressure of the trade that sees as many as 15,000 visitors a day travelling by boat from the mainland, to visit its once-idyllic streets and squares. 
 
 One local official told The Daily Telegraph: "You can't fit a litre-and-a-half into a litre pot." 
 
 Florence, Barcelona and some Greek islands like Santorini have suffered too, and it was perhaps Venice which experienced the problem first. Its population has been falling since the 1950s, effectively forced out by the hordes of cruise-ship visitors. 
 
 Why numbers are increasing 
 
 Tourism, of course, remains essentially a good thing and in the developed world we nearly all do it. 
 
 It means trade and cultural exchange and it's both a symbol of rising prosperity and a generator of future wealth. 
 
 Image copyright Getty Images Image caption Not everyone in Barcelona is happy with the summer 'invasion' of tourists 
 
 Part of the "problem" is that travellers from traditional sources like the UK, Germany and the USA are increasingly being joined by the new middle classes of countries like Russia, China and India. 
 
 Add to that the issue of security, which means that many tourists feel safer in Europe than they do in alternative destinations like Tunisia, Turkey or Egypt, and it's hard to see the numbers falling any time soon. 
 
 It will fall to local governments in places like Dubrovnik and Capri and Venice to find a way of reducing those growing pressures. 
 
 For now, ideas like installing turnstiles on ancient squares and pedestrian traffic lights on crowded streets may sound rather fanciful. 
 
 But if that tourist tide keeps rising they might start to seem a little more tempting. ||||| They are assaulted on a daily basis by giant cruise ships , uncouth tourists, feral pigeons and flooding caused by high tides. 
 
 Now Venetians have declared war on a new foe – noisy suitcases on wheels. 
 
 Shopkeepers, cafe owners and residents say they are being driven half mad by the incessant rumble of visitors trundling their luggage along the city's narrow alleyways and up and down delicate stone bridges. 
 
 The wheeled suitcases are essential in a city without roads, where tourists have to reach their hotels either by water bus or by walking. 
 
 Now Venice council wants to introduce a ban on luggage equipped with hard rubber wheels, forcing the city's 27 million annual visitors to instead use suitcases that roll on air-filled, softer wheels that make less noise. 
 
 The authorities are concerned about "growing noise pollution" caused not only by tourists using wheeled luggage, but local businesses wheeling goods around on trolleys, the council said in a statement. 
 
 The daily rumble of wheeled suitcases was giving Venetians "serious discomfort" and also causing the "progressive deterioration" of centuries-old paving slabs, marble steps and foot bridges, it added. 
 
 The council, which is under special administration after a corruption scandal earlier this year forced the resignation of the mayor, wants to introduce the ban next May. 
 
 After that, anyone with a noisy, hard-wheeled suitcase will be liable to a fine of up to 500 euros. 
 
 For a city wrestling with so many problems – rising waters caused by global warming, an exodus of locals because of high rents and property prices, and a daily invasion of 60,000 tourists – the issue of noisy luggage may seem trifling. 
 
 "Is that true? Jesus, that's crazy," a French tourist told Il Gazzettino, a local newspaper, when told that his suitcase on wheels will be banned within a few months. 
 
 A young Italian woman pulling her suitcase along the banks of the Grand Canal said: "It seems to me to be a pretty stupid idea." 
 
 But the council insists that the issue is a real one and that locals living near hotels and bed and breakfasts dread the moment when groups of tourists arrive and leave, dragging their heavy loads over the city's stone paving stones, known as "masegni". 
 
 The council admits that the new law will be hard to enforce, with thousands of tourists arriving by train, plane and boat every day, and that trolleys with pneumatic wheels are hard to come by. 
 
 The vast majority sold around the world have wheels made of hard resin or plastic. 
 
 The authorities hope that a firm will spy an opportunity to produce a new line of Venice-friendly suitcases. 
 
 "The law won't come into effect until May, so hopefully by then one or two companies might start producing trolley suitcases with air-filled wheels," said Maurizio Dorigo, the council's planning director. 
 
 The new, hushed suitcases would benefit not only Venice but the historic centres of many Italian cities, he said. "The historical centres of lots of other places have the same problems as us – Rome, Florence, Siena. There needs to be a way for tourists to wheel around their luggage without making that crazy noise." 
 
 Long-suffering Venetians will be exempt from the new law and will be free to clunk their noisy suitcases up and down the canal banks. ||||| For Barcelona, Tourism Boom Comes At High Cost 
 
 Enlarge this image toggle caption Manu Fernandez/AP Manu Fernandez/AP 
 
 On a mild, sunny afternoon, hordes of tourists stroll down Barcelona's famous tree-lined pedestrian avenue, La Rambla. They love it — the weather, the tapas, the laid-back bohemian vibe. One tourist from Australia says he's visited Barcelona 12 times in 10 years. 
 
 But the city doesn't always love them back. 
 
 In January, thousands of Barcelona residents marched down La Rambla and "occupied" the entrance to a hotel there, to protest the volume of tourists and gentrification in the city. 
 
 Such rallies began in the summer of 2014, after a group of Italian tourists rented a flat for a bachelor party in an old fishermen's barrio on Barcelona's seafront. One morning, three of the visitors were photographed gallivanting around the neighborhood grocery store — stark naked — as elderly neighbors looked on, aghast. Their antics made the local newspapers and sparked protests which have spread across the city in recent years. 
 
 That incident became a symbol of tourists gone wild in Barcelona, and gave birth to neighborhood anti-tourism groups. 
 
 "The promotion of tourism, and all these tourist apartments, is actually driving neighbors out," says Martí Cusó, a member of one anti-tourism group in Barcelona's Gothic quarter, where his family has lived for three generations. 
 
 Enlarge this image toggle caption Lauren Frayer for NPR Lauren Frayer for NPR 
 
 He takes NPR on a tour of his barrio, where the dry cleaner and local tailor have closed, their storefronts converted into a 24-hour mini-mart and souvenir shop. A city square that used to be entirely residential is now lined with hotels. The only remaining apartment building has just been renovated into luxury condos, mostly to be used as vacation homes for wealthy foreigners. 
 
 "All the community that was living here has been broken — completely broken," Cusó says. 
 
 At his local market, the centuries-old La Boquería, most people are not buying vegetables. 
 
 "They crowd the passageways, taking photos, so regular people can't do their grocery shopping," says Rocí Gayo, who has sold fruit at La Boquería for 20 years. "Out of 20 tourists, if I'm lucky, maybe one will buy one piece of fruit — but no more." 
 
 Two years ago, City Hall banned tour groups of 15 or more people from entering the market altogether on Saturday and Sundays before 3 p.m. — peak shopping hours. 
 
 Tourism does bring revenue, and has helped Barcelona grow. It currently makes up about 12 percent of Barcelona's economy — up from less than 2 percent before the 1992 Olympic Games showcased this city to the world. 
 
 But tourism revenue is not shared as equitably as many locals would like. As old rent controls expire, restaurant and hotel chains have gobbled up mom-and-pop, family-run businesses. With more than 30 million annual tourists in a city of 1.6 million residents, there may be more tourist rentals in Barcelona than year-long leases for full-time residents, says Janet Sanz, the deputy mayor in charge of urban planning. 
 
 Enlarge this image toggle caption Lauren Frayer for NPR Lauren Frayer for NPR 
 
 "It started with the '92 Olympics, and it's opened to the world," Sanz told NPR in an interview at her office. "We understand that other people love our city. But we're becoming a tourist theme park, every time a grocery store closes and a souvenir shop takes its place. People live and work here. It's not just a fun weekend place." 
 
 In January, City Hall banned new hotel beds in the historic quarter. Late last year, it slapped the home-sharing companies Airbnb and HomeAway each with 600,000-euro fines ($634,000) for listing unlicensed tourist rentals. 
 
 Such companies have become targets of public anger over rising real estate prices and a diminishing supply of year-long leases. Homeowners can make much more money renting short-term to tourists than long-term to locals. 
 
 Sanz estimates there are 10,000 licensed, short-term rental flats in the city, and about 7,000 illegal ones. 
 
 "We agree with them on the need to crack down on unwelcome commercial operators," says Patrick Robinson, regional director of public policy for Airbnb, who traveled from London to negotiate with Barcelona officials. "But the city also needs to come to terms with the fact that Barcelona residents are using space in their homes to generate much-needed income at a time of economic stress." 
 
 Starting this spring, Airbnb has agreed to limit homeowners to one property listing per person in the city center. But it disputes the city's rule that every listing must have a tourist license — which requires a long bureaucratic process — especially if you're renting out part of your own home. 
 
 That's the new sharing economy, Robinson says, and Airbnb helps disperse tourists throughout the whole city. 
 
 "More than 70 percent of guests who travel to Barcelona with Airbnb say they want to live like locals do. That is why so many people are now staying in areas that don't normally see tourists," Robinson says. "This is a different kind of tourism." 
 
 Enlarge this image toggle caption Lauren Frayer for NPR Lauren Frayer for NPR 
 
 The city frames the licensing dispute as a security issue and encourages tourists to ask landlords if they have a tourist license before they rent. Otherwise, city inspectors could evict tourists from unlicensed apartments at a moment's notice, Sanz warns. 
 
 Late last year, Sanz and her City Hall colleagues conducted a citizens' survey. Residents responded that their No. 1 concern is still unemployment — currently at around 10 percent — even though the Spanish economy has rebounded from the economic crisis. 
 
 Their No. 2 concern: Too many tourists.
– It all started with Venice. The Italian port city on the Adriatic Sea has seen its population dwindle since the 1950s as locals are forced out by what the BBC calls "hordes of cruise-ship visitors." Nowadays, the problem of cruise ship tourist invasion has spilled over to many other ancient port cities, perhaps most notably Dubrovnik in Croatia on the other side of the Adriatic. Thanks in part to Game of Thrones being set there, five or six times the number of local residents (only 1,500 people live within the Old City) storm the gates every day in the summer. And that's not counting the thousands of tourists already staying in hotels and rentals; nearly all the city's stone houses are now devoted entirely to housing tourists. France24 reports that access to the Old City may soon be restricted. "When I first got here, I'd stand back if I saw that people were taking photographs of each other," says the editor of the Dubrovnik Times. "Now there are so many people that I know if I did that, I'd never get anywhere here." A local official chimes in that "you can't fit a liter-and-a-half into a liter pot." In Barcelona, per the Local, the situation has become so dire that more locals cite tourism as a problem than unemployment and working conditions. The deputy mayor says it's not "tourist phobia," but rather that, with some 30 million visitors spending at least one night in Barcelona last year, there's a "concrete malaise caused by overcrowding." Even in a more out-of-the-way destination like Iceland, tourists far outweigh the tiny local population. (Some say tourists are physically ruining Iceland.)