The Rock? The Bridge? The Opera House? Maybe the Reef?

Which single icon says the most about Australia and what defines us?

Many would point to Uluru as the spiritual heart of Australia, yet so few Australians have actually been there.

Others would say you can't go past the Bridge and Opera House; together they make up one of the most recognisable scenes in the world.

The Great Barrier Reef does have the distinction of being the largest living structure on the planet, but is perhaps less tangible as a singular image of Australia.

Tourism NT is stirring up its tourism counterparts with a survey showing 57 per cent of Australians believe Uluru is the nation's most iconic landmark.

Only about four per cent of us actually went there last financial year, yet we apparently feel a strong connection with our Red Centre.

Tourism NT claims “the Harbour Bridge is falling down” in popularity: even in Sydney, nearly half the population rate Uluru our most iconic destination.

However, the third-party survey of 1000 Australians revealed frightening ignorance of the Northern Territory and the scenes we seem to hold so dear.

Nearly two-thirds of the Aussies surveyed were so unfamiliar with the NT they believed it had more crocodiles than people, while one person in ten believed Arnhem Land was a mythical place from a children's book.

Unbelievably, 12 per cent of those surveyed didn't know Darwin was the Northern Territory's capital or believed the state was bordered by NSW or the ACT.

And despite the Top End receiving about 1700mm of rain each year, nearly three quarters believed the NT was as dry as the Sahara Desert.

(I do hope the Department of Education is reading this.)

It's important to make a distinction between what Aussies treasure and how international visitors perceive Australia, but research by Tourism Australia shows natural attractions are by far the biggest drivers of visitor demand.

Our beaches take number one spot for what international visitors want to see, followed by our wildlife, the Great Barrier Reef, rainforests and national parks.

The results vary by country but overall our major cities are only in ninth spot as tourism drawcards.

Our coastal lifestyle rates highly, with Aboriginal culture and the Outback well down the list.

Visitor numbers tell us little, given huge differences in accessibility, but for the record Uluru gets about a quarter of a million visitors a year, while the Opera House reports more than eight million.

It's impossible to measure visitor numbers for the Sydney Harbour Bridge, but Bridgeclimb reports more than three million people have climbed its span over the past 16 years.

Australia's biggest inbound tourism operator, the AOT Group, is not ready to play Tourism NT's game, saying there is no single icon that defines Australia in the minds of international travellers.

The director of sales and marketing for the group, Michelle Kenna, says the drawcards vary by the traveller's country of origin, age and interests.

Kenna says Sydney Harbour, the Bridge and Opera House are major drawcards for all Western markets and Sydney is included in most itineraries.

“The standard harbour, rock and reef itinerary is still popular and the flight connections between the three mean this is still a relatively seamless option for first-time visitors,” she says.

For more adventurous travellers, be they backpackers or five-star, Kenna believes Alice Springs, Kings Canyon and Uluru offer the greatest adventure package, along with the Great Barrier Reef; particularly islands such as Heron and Lady Elliot that are more focused on eco-experiences.

I was surprised to hear that many international tourists have South Australia's Kangaroo Island at the top of their list; not because it is not deserving but because it has such a low profile compared to other Aussie destinations.

Kenna says KI is the “must see” place for Italian visitors in particular, due to its abundance of wildlife and picturesque coastlines.

German and French travellers are drawn to Darwin, Katherine, Arnhemland and Kakadu – the latter of which was voted by six out of ten Aussies as our “best kept travel secret”, if you can possibly call Kakadu a secret.

Kenna says Western Australia is popular with UK visitors, partly due to flight access, but the mining boom has made it expensive.

The big drawcards in the West are the wine regions, Exmouth, Ningaloo Reef, Broome and the Kimberleys; again, places that many Australians have never seen.

What do you think is Australia's most iconic site? What do you think is the 'must see' for foreign visitors? Post your comments below.

jane.fraser@fairfaxmedia.com.au