A new index created by Australian travel company Intrepid has revealed the countries suffering from the most "overtourism", along with the nations with "undertourism".
The index compares total visitor arrivals in 2016 to the permanent population to create a "tourism density index".
While Iceland has been in the news recently for its incredible tourism boom, with about six tourists to every local, the country actually comes second to Croatia as the country with the most tourists per head of population, according to Intrepid's index.
Croatia saw 57,587,000 tourists in 2016 and with their meagre population of 4,170,600, that measures 1380.78 per cent of the country's population – nearly 14 tourists to every local.
Hungary is the third most "overtouristed' country in the world, with 52 million people visiting in 2016 measuring 538.71 per cent of the country's population, about five visitors per local.
Other countries in the top 10 list include France, Denmark, Czech Republic, Singapore and Spain.
The worldwide tourism boom has been creating problems in some of the world's most popular tourist destinations, notably European hotspots such as Venice and Barcelona.
A backlash from locals in these cities has seen tour buses vandalised and graffiti plastered on walls telling tourists to go home.
Venice recently created tourist-only routes to the city's most popular landmarks – St Mark's Square and the Rialto Bridge – away from locals who have for years complained that their day-to-day lives are made a misery by the invasion of visitors.
Meanwhile, in Amsterdam, which is also struggling with increasing tourist numbers, authorities announced the city will ban Airbnb short-term rentals in busy areas, divert cruise ships from docking in the centre, and crack down on "fun rides" like Segways, beer bikes, and boozy boat trips.
Intrepid conducted the research as part of its first Adventure Travel Index, which looks at the travel habits of the tour company's travellers.
The research also found that travellers both old and young like to travel to more exotic destinations such as Peru, Cuba and India, almost half of their travellers choose to go solo, and most of them are female.
It also indicated that their travellers define "adventure travel" as getting off the beaten track or trying something new, rather than making a death-defying leap.
"Adventure travel is one of the fastest growing sectors in tourism – and Australians are leading the way," Intrepid Group CEO James Thornton said.
"By going outside of our comfort zones, challenging ourselves and getting off the beaten track, adventure travel can change the way people see the world."
The travel trends survey revealed the return of "forgotten destinations" such as Ethiopia, Zimbabwe, Moldova, Greenland and Kazakhstan.
Active adventures, such as cycling trips, increased 287 per cent in 2017, increasing in popularity with overworked professionals seeking to recharge their batteries.
But the drive towards sustainable travel will be headed by Millennials and their younger Gen Z counterparts who will look to responsible tourism, which is where density ratios such as Intrepid's come into play.
These travellers will be spearheading travel to the "undertouristed" countries such as Tanzania, Papua New Guinea, Kenya or Indonesia where the tourist-to-population ratios fall under 5 per cent.
Given the popularity of Bali, Indonesia might seem a surprising country to make the list. But when factoring in the country's population of more than 260 million, and the fact that many parts of the country remain undiscovered by tourists, the ranking makes sense.
Intrepid also predicts that Iran will be one of the next travel hotspots. It remains largely untapped by tourists, who make up 6 per cent of the country's total population.
"People who travel with us to Iran are always surprised to the extent at which locals welcome them," Thornton said.
The Adventure Travel Index combined Intrepid statistics, externally commissioned third party research, studies from Deloitte, Nielsen and a survey of local tour leaders across the globe.
The Top 10 countries for overtourism
- Croatia (57,587,000 tourists to 4,170,600 locals - 1380.78%)
- Iceland (1,891,000 tourists to 334,250 locals - 565.74%)
- Hungary (52,890,000 tourists to 9,817,960 locals - 538.71%)
- Denmark (28,692,000 tourists to 5,731,120 locals - 500.64%)
- France (202,930,000 tourists to 66,896,110 locals 303.35%)
- Czech Republic (30,915,000 tourists to 10,561,630 locals - 292.71%)
- Singapore (16,404,000 tourists to 5,607,280 locals - 292.55%)
- Cyprus (3,286,000 tourists to 1,170,130 locals - 280.82%)
- Greece (28,071,000 tourists to 10,746,740 locals - 261.20%)
- Spain (115,561,000 people to 46,443,960 locals - 248.82%)
The top 10 countries for undertourism
- Tanzania (1,284,000 tourists to 55,572,200 locals - 2.31%)
- Papua New Guinea (198,000 tourists to 8,084,990 locals - 2.45%)
- Kenya (1,340,000 tourists to 48,461,570 locals - 2.77%)
- Indonesia (11,519,000 people to 261,115,460 locals - 4.41%)
- Egypt (5,399,000 people to 95,688,680 locals - 5.64%)
- Mozambique (1,715,000 tourists to 28,829,480 locals - 5.95%)
- Iran (4,942,000 tourists to 80,277,430 locals 6.16%)
- Colombia (4,048,000 tourists to 48,653,420 locals - 8.32%)
- Sri Lanka (2,168,000 tourists to 21,203,000 locals - 10.22%)
- China (141,774,000 tourists to 1,378,665,000 locals - 10.28%)
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