Tourists overwhelm European hotspots as popular sites swarmed with holidaymakers as early as 8am

Experts have said the industry is "hitting max capacity earlier and earlier", noting that certain countries were not "coping rather well".

Popular locations, including the Acropolis in Athens, the Trevi fountain in Rome and the Vatican have faced waves of tourists during the latest summer heatwave.

Kevin Schreck, a travel adviser and tour guide based in Valencia, told the Daily Mail: "In this area of the Mediterranean, tourism has been going up consistently for the past three years, and we've been hitting max capacity earlier and earlier."

Even as areas of Europe face anti-tourist protests and repeated heatwaves, the number of tourists have risen, he said.

The number of tourists had become "rather unsustainable", the tour guide admitted, noting that Spain had not coped with the rise well.

And Nero Line, a luxury retail provider in Spain, said peak weeks had filled earlier, with "less room to move" compared to previous seasons.

"Spain is on course for 100 million international arrivals this year, the strongest summer in its modern tourism history," the company added.

Conflict in the Middle East sending tourists who may have vacationed in destinations such as Turkey, Cyprus or Egypt may be driving the rise in tourism in Europe, the company argued.

Footage from inside packed trains in Italy showed passengers forced to stand in the aisle, pressed against each other.

Streets were also seen to be jam-packed around the Trevi Fountain, Italy's most popular tourist location.

In an effort to combat the swarms of tourists, a €2 (£1.70) fee was introduced in February for visitors to view the iconic 18th-century fountain between peak hours.

One tourist on social media admitted the crowds in Rome were "not for the weak", adding that they "almost died" pushing their way through.

Huge queues snaked through the Vatican, as culture vultures escaped the heat to enter its museums - the second most visited art museum in the world, behind the Louvre.

Another holidaymaker filmed huge crowds shuffling through the Acropolis in Athens as she toured the ancient citadel at 8am, hoping to dodge hordes of sightseers.

Europe has been swept by a series of anti-tourism demonstrations and protests.

Protests in the Balearic Islands have increased in intensity ahead of the solar eclipse on August 12 - northern Spain is one of the few tourists hotspots within the zone of totality, where the moon fully covers the sun.

Earlier this week, armed riot police clashed with anti-tourist protests in Mallorca - the third year of mass protests on the island.

One protester sustained a large gash in his head as a result of the clashes, pictures from the scene revealed.

Demonstrators were pictured holding signs which read "tourists go home", "save Majorca", and "less tourism, more life".