THIRTY years ago Shenzhen, in south China's Guangdong Province, was a dreary, frontier village off limits to ordinary Chinese because it borders Hong Kong, then a British colony.

An old friend of mine, distraught over her failed marriage to a Beijing diplomat, attempted to go to Hong Kong in 1957 to join the family she hadn't seen since 1949 -- walking along the railroad tracks near Shenzhen under the cover of darkness. She was arrested by a border patrol and spent the next 20 years in prison.

When I first visited Shenzhen in 1986, it had already been transformed from the obscure village where my friend had trespassed on that fateful night into to a boom city.

Shenzhen was one of the four special economic zones set up by Deng Xiaoping in 1980 to pilot his bold economic reforms. But the border city was still off limits to domestic travelers. I had to obtain a travel permit from local public security bureau before going.

After six years of rapid construction, Shenzhen already showed the promise of a dynamic city. Skyscrapers were mushrooming everywhere, many still in scaffolding. This city of immigrants felt young, ambitious, open-minded and entrepreneurial.

I visited Shekou and gazed at the blurred skyline of Hong Kong across Deep Bay. The most memorable souvenir from that trip was a double-deck cassette player I bought with my two months' salary. It was my first luxury gadget.

On my second visit two years ago, I was amazed to see the city's expanding boundaries as the local population now exceeds 10 million. The city, now No. 4 in GDP ranking in China, is home to the country's third stock exchange -- after Hong Kong and Shanghai.

The listings include IT heavyweights such as Huawei, ZTE, Konka, Hasee and Tencent, plus China's largest property developer, the Vanke Group, the electric car maker BYD, and the world's largest golf course -- the 216-hole Mission Hills Golf Club.

I noticed four international hotels were under construction in the vicinity of the Shenzhen Convention & Exhibition Center, a landmark in central Futian District.

When I was there again two weeks ago, they were all in business. I stayed in the brand-new Ritz-Carlton Shenzhen. Sipping a cocktail from a coconut in a rooftop bar next to a swimming pool, I marveled at the night view of Shenzhen, a city that has become a trendsetter and role model in China.

Not far from my hotel is the Shenzhen Civic Center, a unique building under the largest roof in the world: It covers 30,000 square meters and weighs 9,000 tons. The building houses the city government and the one-stop citizen service center.

After years of giddy development, Shenzhen is going all out to minimize the impact of urbanization on the local environment and become an eco-city. Its "green" efforts have materialized in patches and strips of greenery on street corners and along roads.

Looking from my room on the 22nd floor of Ritz-Carlton Shenzhen, I mistook a nearby shopping mall for a street park because its vast rooftop is covered with grass, flowers, shrubs and trees. Rooftop gardens and balcony flowers are a common sight in Shenzhen.

The city's resolve to restore ecological balance is also reflected in the creation of Hongshulin Ecological Park, a mangrove reserve in central Futian District. A tour guide claimed it is the world's only nature reserve in a metropolitan area.

The park is a haven for 179 species of coastal and migratory birds that feed in the bay. Minutes after I reached the edge of the reserve, I saw pelicans gliding gracefully over the water. Cormorants, egrets and thousands of other birds dotted the shoals in the bay.

The mangroves are in harmony with the nearby residential high-rises. The guide said many households in the buildings have telescopes and binoculars to watch birds in the reserve, which also attracts birdwatchers from abroad. These included Prince Philip of England and the late Prince Claus of the Netherlands.

Another must-see of Shenzhen is famous Dafen Village, a one-time rural hamlet that has been engulfed by urban development. This block of low-rise buildings is filled with galleries on the street level and workshops on upper floors where as many as 8,000 painters churn out a staggering volume of oil paintings -- knock-offs of Van Goghs, Monets, Dalis, Andy Warhols and works of top Chinese artists. These include Yue Minjun, whose self-portraits in eerie laughter have fetched millions of US dollars through Sotheby's.

My tour guide said the artists are paid like factory workers and there is a division of labor: Some just paint eyes, some paint only hair and others specialize in flowers or fabrics. This stream of production would have made Henry Ford proud, as one Western visitor commented.

This systematic reproduction of world-famous paintings began in the mid-1980s when a Hong Kong art dealer was impressed by the skills of two young village brothers eking out a living by making imitation art. He began to commission them for pieces he would sell a high price to foreign buyers.

Gradually, a new industry was born, absorbing poor artists from all over the country. Many are rural youths with no skills who learned the knack of painting in training classes held by their employers.

A 25-year-old painter, Chen Quan, says it took him only two days to crank out a reproduction of a Yue Minjun and he has done hundreds of his paintings.

A fake Yue Minjun painting sells for only 250 yuan (US$33) in Dafen village.

Walking in the maze of galleries, I also found that many of them offer portrait painting for customers based on their favorite photos. It takes them just two weeks to deliver the commissioned portraits, priced according to the number of faces, 400 yuan for one person, with each extra face costing another 200 yuan.

Since I didn't leave enough time to appreciate the myriad artworks in the village and bargain with shop owners, I decided to come back in near future. Then I will spend a day or two hunting for really great pieces that will dumbfound unsuspecting visitors to my apartment. Shenzhen holds still more secrets.