Unesco experts recommended on Monday that Venice and its lagoon be added to its list of World Heritage in Danger, because Italy is not doing enough to protect the city from the effects of climate change and mass tourism.
The UN cultural agency's 1,157 World Heritage sites are regularly reviewed and at a meeting in Saudi Arabia in September, 21 Unesco member states will review more than 200 sites and decide which to add to the danger list.
The experts recommend that member states put nearly 10 of these sites on the danger list, among which are the historic port centre of Odesa, Ukraine, the town of Timbuktu in Mali, and several sites in Syria, Iraq and Libya.
Other sites recommended for the danger list this year are the cities of Kyiv and Lviv in Ukraine.
"Resolution of long-standing but urgent issues is hindered by a lack of overall joint strategic vision for the long-term preservation of the property and low effectiveness of integrated co-ordinated management at all stakeholder levels," Unesco said.
Unesco said corrective measures proposed by the Italian state are "currently insufficient and not detailed enough".
It said Italy "has not been communicating in a sustained and substantive manner since its last committee session in 2021, when Unesco had already threatened to blacklist Venice".
The agency said it hoped that "such inscription will result in greater dedication and mobilisation" of local and national stakeholders to address long-standing issues.
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A representative for the Venice Municipality told Reuters that the city would "carefully read the proposed decision published today by the Centre for Unesco's World Heritage Committee and will discuss it with the government".
Venice, known for its canals and cultural sites, has been struggling with mass tourism for years.
On a single day during the 2019 Carnival, about 193,000 people squeezed into the historic centre.
Venice has been preparing to introduce a fee for day-trippers to control visitor numbers, but has been delayed by objections.
Venetians plead 'please don't come' as tourists jam city
The city's famous Rialto Bridge was jammed with tourists on Monday.
Taking selfies, licking gelato and wheeling suitcases, the visitors seemed happily oblivious to the possible downgrade Unesco said was due to the risk of "irreversible" damage.
New York tourist Ashley Park, 28, said she knew it would be crowded in Venice, but it wasn't ruining her vacation.
"Obviously if we lived here with all these tourists it wouldn't be fun," Ms Park said.
Among the crowds on the historic bridge was city worker Diego Nechifrovo, 23, wearing an EnjoyRespectVenezia T-shirt, who was busy keeping an eye out for misbehaving tourists.
"Sometimes I see someone throwing away his cigarette or walking around without a T-shirt," he said, noticing a bag of potato chips discarded on the doorstep of a jewellery shop.
The worst? One time a family "sat down right in front of the Doge's Palace and started to set up a picnic".
A few weeks ago, a distracted tourist fell into the water, Mr Nechifrovo said.
"He was trying to get a good photo".
Not far away, a seller of watercolours had a sign on his stand pointing to St Mark's Square.
"That's all they want to know," said the native Venetian, Claudio. "They come to Venice because it's Venice. That's all."
The days of educated tourists visiting and enjoying the city's many churches and museums were over, he said.
"Those who come now don't even know what a museum is. It's not cultural tourism," Claudio said.
"They need to go to the beach, or the mountains but not here," he lamented. "Please don't come any more."
About 3.2 million tourists stayed overnight in Venice's historic centre last year, according to official data, a number that does not include the thousands of daily visitors who do not spend the night.
"It's pretty beautiful – it's a draw," said US tourist Mike McWilliams, 53, who had just arrived in the city for a two-day visit with his family.
Back at St Mark's Square, city worker Lorenzo Seano, 21, was struggling to keep tourists from sitting on the steps of the surrounding arcades.
The problem of too many tourists invading cities went well beyond Venice, Mr Seano said, but no one in government had tried to tackle the problem "on a structural level".
"After all, there's a ton of money coming in," he said.