A zip wire shoots riders at 100 kilometers an hour over Eden Project's two biomes. For adrenaline junkies, it's a thrilling view of the world's biggest indoor rainforest and Mediterranean landscapes.

The more faint-hearted take the traditional route, strolling through the botanical gardens that fill much of the rest of the park, before exploring the famous climate-controlled domes.

Around a million visitors take in the experience each year. As well as educating the public on environmental issues, the project has boosted an economically deprived part of the Cornish countryside in southern England.

At the turn of the millennium, the scene was very different. Where glittering domes now rise from lush gardens, there was a giant crater left by a 150-year-old clay mine.

It took two-and-a-half painstaking years to fill the site with thousands of tons of soil.

"It was decided early on that we wouldn't just go and raid someone else's topsoil and denude another area," explains lead horticulturist Julie Kendall. "So we manufactured all of our soil. The soil was sterile, so we even had to go and buy worms."

The wrigglers are vital for soil fertility, Kendall adds.

Transplanted worlds

Next, the biomes themselves were erected. The tropical dome is 50 meters high and kept at a sweltering 35 degrees Celsius (95 degrees Fahrenheit) during the day.

A forest of rubber, banana and bamboo trees thrive with the help of insects, lizards and birds that protect the plants from pests.

"Anytime we buy a plant, it has to go into quarantine, so that we bring it in as clean a plant as possible - because if it goes into the rainforest, pests and diseases just grow exponentially," Kendall told DW.

At around 25 degrees Celsius, the Mediterranean Zone is slightly cooler, replicating the hot, dry summers and frost-free winters of more temperate parts of the world. Among the vast and varied indoor landscape are grape vines; as well as cork, citrus, olive and nut trees.

And the project is still growing. Eden is to upgrade the rainforest, put in weather systems and build a third biome that will focus on the invisible world and pay tribute to recent advances in microbiology.

An Eden for every continent?

Eden is now expanding beyond the British site, too. When the park opened in 2001, founder Sir Tim Smit vowed to spread its environmental message to every continent.

As the Eden Project marks its 15th anniversary, that dream is coming true. Developers in several international locations are keen to replicate the park's success in revitalizing environmentally damaged land.

Last year, Eden's owners signed a deal with Chinese firm Jinmao Holdings to build a new Eden Project in Qingdao, midway between Shanghai and Beijing on China's eastern coast. The Chinese Eden Project is to be four times the size of the original in Cornwall.

Rather than a rainforest, the new attraction will be themed around water, which has special resonance in Chinese culture. Wetlands bordered by two rivers and the China Sea will need to be restored.

"We always say - give us your poison," Smit told DW, explaining that the Qingdao site has suffered from phosphate and salt poisoning.

"So we've got to make the land good again, just like we did here."

From terror to beauty

And plans for Eden's third project are taking shape at another environmentally damaged site - on the Australian island of Tasmania.

As part of a new multi-million dollar harbor-front redevelopment at Macquarie Point dockland in Hobart, Eden is planning an attraction that pays homage to the Antarctic.

Australia is the global center of Antarctic research, with hundreds of scientists based at the University of Tasmania, Smit says.

The vision is a "bold and daring" story of how climate change is affecting the continent's ice shelf. Smit wants visitors to be powerfully confronted with the reality of climate change.

"People will come and they'll be so scared, they'll want to leave," he said. "When they've finished being scared, they're going to be so lonely, they're going to cry for their mothers. And when they've finish crying for their mothers, we're going to show them such beauty that comes out of that fragility, that they will view the natural world in a way they've never done before."

Not just for show

Both new projects have been welcomed by local green groups, who have highlighted Eden's solid eco-credentials.

Smit dismissed the idea that China - one of world's largest polluters - and Australia - whose massive mining projects have inflicted huge environmental damage, could be buying an association with Eden to improve their image.

"My instinct is that this is not greenwashing at all," said Smit. "This is actually a deep-seated need that people have as they all, at different speeds and in different places, come to terms with the fact that change has got to happen."