'There's physical heritage, which translates primarily as architecture; cultural heritage, which broadly refers to traditional dress, dance, performances and so forth; and natural heritage, which is the physical environment,' he said of the forum's key topics.

While heritage tourism offers inherent and practical benefit to the nation and its huge domestic travel market, as well as the big and expanding Asian market, Dr Lew says it has the greatest potential for drawing vast numbers of visitors from North America, Europe and Australia. 'China is now the third largest tourist destination in the world after Spain and France. The United Nations World Tourism Organisation [UNWTO] predicts China will surpass Spain to become the most visited country in the world by 2020,' said Dr Lew.

Tim Oakes, another US expert watching the China tourism juggernaut, said: 'I think it will happen much sooner that that. The director of Asian studies in the department of geography at the University of Colorado, Boulder, has been researching China's tourism development since 1991.

Dr Lew said: 'A lot of people from around the world want to travel to China - and China is doing everything possible

to promote travel and tourism to support this. China is so big and so diverse - far more so than the United States.'

Raising international awareness of just how diverse - and the scope and scale of the country's attributes - was a challenge being addressed, he said. 'Western tourists coming to China generally know about a few famous places - the Great Wall, the Imperial Palace, the karst typography at Guilin , the terracotta soldiers in Xian and so forth. So this is what they want to see,' said Dr Lew.

'But it's what the domestic tourist wants to see as well. The result is that these World Heritage Sites get overcrowded. The question is, how do you protect these iconic places?' One of the best ways, said Dr Lew, was to steer tourists to lesser-known attractions and to develop new ones.

The coming boom and fears about congestion at the big-name attractions had prompted the UNWTO to start pushing Silk Road tourism through western China and into Central Asia, said Dr Lew.

'Silk Road trips are growing in popularity with foreigners,' said Stanley Toops, a China specialist in the department of geography at Miami University, Florida, who has been researching the tourism landscape of Xinjiang province for more than 20 years.

'Tourists from Japan, Hong Kong and Taiwan see it as the historic Silk Road of their ancestors, and the path of Buddhism; Europeans see it as part of the exploration phase of the late 1800s Great Game, or Marco Polo; Russians see it as business; Kazakhs and Uzbeks see it as part of the neighbourhood; many visitors from the United States don't have an idea of the place - other than that it's different,' said Dr Toops.

The big-picture potential for tourism in China is huge, said Hilary du Cros, a professor at Macau's Institute for Tourism Studies and a keynote speaker at the July conference.

'Now the market is principally mass sightseeing tourism conducted in fairly brief tours,' she said. 'I'm hoping it will develop and mature to include more Special Interest Tourism segments, where tourists have a deeper interest in the places they visit or events they attend. The trick is to spread the benefits so that trip itineraries don't just include icon attractions,' she said.

Keith Dewar, professor of tourism and hospitality at the University of New Brunswick, Canada, recently completed tourism plans for Harbin and Hangzhou - as part of larger city plans - in affiliation with the China Academy of Urban Planning and Design, Beijing.

Dr Dewar maintains it has almost become a cliche to say the growth of the country's infrastructure is phenomenal. He refers to huge growth in expanding cities, better roads, faster and more modern trains, a good air passenger service and easier access for international tourists. 'People often think of China as having crowded cities and little else. But there are places of great natural beauty, from the tropical forests of Yunnan to the boreal forests of Heilongjiang ,' said Dr Dewar. 'Something that puzzles the new Chinese middle class: they want to show me their modern cities while I want to see their farm villages and smaller towns.'

Dr Lew said: 'If you have a sense of wonder at what can be done in a short period and the scope of their ideas, China is really amazing.'

The first time Dr Lew went to Guilin was in 1992, with his father and two sisters, to visit his father's tiny village, Kaymay. 'You can spell it how you want,' he said, laughing. ''Kay' means flag and 'may' is the tail of the flag. The furthest and most remote among a small group of villages, the only way to get there was on a motorcycle or bicycle because the road turned into a trail.'

More recently, Dr Lew went to the opening of the Guilin bridge project. 'I've seen a lot of pretty amazing things in China but that was the most amazing - the old nothing-special bridges replaced by a Golden Gate bridge [San Francisco], an Arc de Triomphe bridge [Paris], and so on. Every city I go to has something new. I'm not saying it's bad. But there are a lot of people who would like to see the old neighbourhoods preserved.'

Professor Oakes said: 'There's a significant push in China to develop heritage tourism sites. But the focus is less on conservation and more on development.

'Old buildings get rebuilt, built landscapes get 'improved' and 'updated', cultural meanings get reinvented and, in most cases, local governments are primarily concerned with generating revenues than with preserving heritage as it's typically understood in Europe or North America. The challenge is in convincing potential tourists that 'modernising' and 'heritage' are not necessarily mutually exclusive, and that China approaches the whole idea of heritage in a somewhat different way,' he said.

Dr Lew was a student in Singapore in 1983 when shops in the city's old Chinatown district were torn down. 'That year the number of international visitors dropped for the first time in 20 years. The decline was among North Americans and Europeans. Suddenly, the government got interested in supporting preservation and preservation took off,' he said.

'The United States went through the same thing. They used to tear everything down. It wasn't until the 50s and 60s that people got upset and that kind of thing stopped. I have faith this will happen in China. But will it happen fast enough?'

When Dr Lew first came to Hong Kong in 1974, as a University of Hong Kong exchange student, he knew little about his Chinese heritage. He had dropped out after a year at university in California, feeling it was a waste of time.

During his first three months in Hong Kong, 'I thought it was hell on Earth,' he said. 'I had never lived anywhere so hot and humid. I never saw a mosquito, but I could hear them and was getting chewed up by them every night.' After three months, he says, Hong Kong got to be OK. 'After nine months, I didn't want to leave.'

One year into his stay, Dr Lew enrolled at the Chinese University and spent 18 months studying Cantonese. Back in California, he studied Putonghua at the University of California, Berkeley. He completed his undergraduate degree in Hawaii, undertook his PhD research on a Fulbright scholarship in Singapore, and got his PhD from the University of Oregon in the US - by which time he'd established himself in the specialist field of tourism geography.

It's this background in tourism research, and his Chinese parentage, that gives him a rare insight into the growing bond between western travellers and the sights the country has to offer increasing numbers of tourists in the years ahead.