File photo: South Lake Park in Tangshan, an old industrial city in northern China's Hebei province. [www.ungou.com]

The whole park, with core scenic areas measuring 28 square kilometers, cost about 2.52 billion yuan (US$370 million) in total.

Li Guangrui, a 76-year-old local, said the change was welcome.

"Years ago, nobody would even come near here. It was smelly and disgusting with all the trash. Now, I come here to do a little exercise almost every day. It's great to see the garbage gone."

According to the EMC, the park is now home to 49 kinds of wild birds including white-headed duck and red-rumped swallow.

But potential benefits from the park go beyond ecology.

Lin Peng, director of the Urban and Rural Planning Bureau of Tangshan, expected South Lake Park to rekindle investment around the previous wasteland and spawn new business opportunities.

The government wants to turn the area into a so-called eco-town spreading 91 square kilometers by 2015. It could hold a population of 400,000.

Instead of coal mining, technology and capital intensive businesses will be developed into Tangshan's pillar industries.

"Without alternative industries, old industrial bases can hardly sustain economic growth in the future," said Mayor Chen Guoying.

Tangshan isn't the only city facing the challenge. A study released by the National Development and Reform Commission in 2002 showed that about 118 Chinese cities had resources-based economies. Among them, 63 rely on coal, 21 on forestry, 12 on non-ferrous metals and eight on metallurgy.

On March 5, 2009, the State Council, or Cabinet, classified 44 of those cities as "resource-exhausted".

Shen Lei, researcher with the Institute of Geographic Sciences and Natural Resources Research of the Chinese Academy of Sciences, said it means three-quarters of the total proven reserve in those cities have already been used.

It also means they face problems such as environmental degeneration and high unemployment rates.

Tangshan does not fall into the "resource-exhausted" category, but it is resource-based which is why it is relying on the South Lake Park Eco-Town to cultivate sustainable development.

The hope is in five to ten years, Tangshan will have new growth engines to contribute at least half of its gross domestic product, said Mayor Chen.

The park is one step on a long road towards that goal.