Tourists follow a tour guide as they walk past Windsor Castle in Berkshire, UK. Reuters
Global tourism spots are affected badly as visitors opt for cheap lifestyle and food. The boom is down to a fast-expanding global middle class combined with a proliferation of budget airlines and online travel agents, which have made travel cheap and easy. A Londoner can fly to the south of France for less than 20 pounds ($25).
It is not the sheer number of tourists descending on Venice that bothers Italian food blogger Monica Cesarato so much as the type of visitor.
Not so long ago Venice was considered the trip of a lifetime, said Cesarato, who runs gastronomic tours there. Visitors took days, even weeks, to explore the City of Canals, spending money in local restaurants and businesses.
Today they pile off cruise ships and coaches, go on whirlwind tours run by non-locals, take umpteen selfies and buy little more than a cheap trinket made in China.
As millions of holidaymakers head off for their summer break, increasing numbers of popular destinations are saying they cannot take much more.
The Belgian city of Bruges is cracking down on cruise ships, Paris wants to limit coaches, Prague is fed up with bikers - and one Thai beach has banned tourists altogether.
While tourism creates jobs and wealth, there is growing awareness of its negative impacts, from environmental damage to the destruction of neighbourhoods as residents are priced out.
The problems have created a backlash, spawning anti-tourism movements and protests from Amsterdam to Rome and Dubrovnik, the Croatian city featured in the TV show “Game of Thrones”.
Mass tourism took off after World War Two. Last year there were 1.4 billion tourist arrivals, up from 25 million in 1950, according to the United Nations World Tourism Organisation, with Europe absorbing half of them.
The nation generating the most tourists is China - 143 million trips abroad in 2017, while France and Spain receive the most visits - more than 80 million a year.
“The perception of going on holiday has shifted from being pretty much a privilege to becoming very much a right,” said Marina Novelli, professor of tourism and international development at the University of Brighton.
She said for decades tourism authorities and ministries have only measured success in terms of increased visitor numbers. “This model no longer works and that’s probably the most important message to get out there,” she said, warning that overcrowding and “Disneyfication” in some places could destroy the charms that draw tourists in the first place.
“If we look at numbers only, and we don’t look in more detail at the impact - economic, social, environmental - we risk killing the goose that lays the golden egg.”
Nowhere epitomises the problems as much as Venice, which attracts 30 million tourists a year to its magnificent canals and bridges.
As visitor numbers soar, the “Queen of the Adriatic” has seen its own population plummet from about 175,000 after World War Two to just over 50,000.
“We used to have a low season when Venetians had time to recuperate. Now it’s all year round and Venetians don’t get the city for themselves anymore,” Cesarato told the Thomson Reuters Foundation.
Stores like bakeries and greengrocers and community services are vanishing as residents bail out. “I can only just see this getting worse and worse,” she added.
UNESCO has threatened to add Venice to its list of endangered heritage sites, partly because of problems with tourism.
Calls to ban cruise ships from the centre of Venice intensified this summer after one hulking liner crashed and a second had a narrow miss.
Travel experts say cruise ships - along with other day-trippers - exacerbate “overtourism” because passengers increase congestion while spending little locally.
Several European destinations including Dubrovnik, Bruges and the Greek island of Santorini, have slapped restrictions on cruise ships. Barcelona’s mayor has also promised action.
Another phenomenon fuelling anti-tourism protests is the rise of short-stay letting platforms such as Airbnb, which are blamed for hiking rents and changing neighbourhoods.
With landlords able to make far more on holiday lets than traditional leases, housing supply has shrunk and residents have been squeezed out. Paris has about 60,000 homes listed on Airbnb, Amsterdam 19,600, Barcelona 18,300 and Venice 8,500, according to Inside Airbnb, a website highlighting the company’s impact on neighbourhoods.
Cities including Palma de Mallorca, Paris, Amsterdam and London have introduced or are discussing measures to mitigate the impact.