For the hundreds of thousands of visitors to Shenzhen each year, it is hard to imagine what the city looked like 25 years ago when the central government first designated it to become a special economic zone. 'Nobody would ever have thought of coming to Shenzhen as a tourist at that time. We had nothing to promote or recommend to people from other cities,' said Shenzhen Tourism Administration head Chi Xiongbiao . Today Shenzhen is the one of the most popular holiday destinations on the mainland, with more than 55 million domestic and foreign travellers visiting last year. The revenue generated by tourism exceeded 38 billion yuan, about 6.1 per cent of the national total. 'During the Lunar New Year this year alone, the revenue of our tourism industry was more than 3.5 billion yuan,' Mr Chi said. 'That is about the same as Beijing and Shanghai combined.' Shenzhen today boasts some of China's most successful indigenous theme parks, including Minsk, which features a 40,000-tonne decommissioned Russian aircraft carrier, and the Windows of the World, with its impressive collection of miniaturised global landmarks. The millions of tourists who flock from inland provinces to Shenzhen are simply trying to catch a glimpse of their own future. The special economic zone has been hailed as the model for China's economic miracle and an example to be copied by the rest of the country. 'Shenzhen is so brand new and modern. It's very clean and advanced. Kunming [Yunnan province's capital] is now becoming more and more like it,' said Zhao Xiaozhou , a visitor from Yunnan. All this gives Mr Chi reason to smile. And he is positive about the future, with Hong Kong Disneyland opening next month. 'The Hong Kong and Shenzhen tourism industries can complement each other,' he said. 'Tourists who go to Hong Kong to see Disneyland won't spend a whole week in Hong Kong. Most of them will drop by and have a look at Shenzhen too.' He estimates the number of visitors to Shenzhen will grow by about 10 per cent after Hong Kong Disneyland opens. 'About 70 per cent of mainland tourists going to Hong Kong will come to Shenzhen first,' Mr Chi said. 'We are confident our travel industry will continue to enjoy a high growth rate. We will also continue to improve our facilities.' One aspect the city's tourism industry will focus on is ecotourism. A government-backed theme park operator plans to spend 4 billion yuan on an ecological park that will open by the end of next year. Mr Chi said billions more had been earmarked for upgrading infrastructure to brighten the city and protect its environment.