A Cornish quarry is the site for a millennium project that aims to tell the fascinating story of humanity's relationship with, and dependence on, plants. Nearly two million tonnes of soil were shifted from an area the size of 35 football pitches. Huge geodesic domes, reminiscent of the eyes of gigantic insects, were anchored on this surface and moulded to the shape of the site. This is the Eden Project, due to open fully at Easter.
Inside one of these "biomes", you find a tropical rainforest; in another, the Mediterranean climate, found around the Mediterranean Sea, the Cape of Good Hope and California, is represented by a warm temperate landscape. The third zone is open-air, and will exploit Cornwall's wonderful climate to contrast plants from the Himalayas and Australasia with the local flora.
The Eden Project had its unlikely roots in the stories of Roald Dahl. He often depicted the plant kingdom as a brooding and malignant force in his books - perhaps because he wrote in his garden shed. While the project's originators began by concentrating on the ghoulish aspect of plants, as Dahl had done, they soon realised there was a greater potential to their idea. Gradually, the focus became people's reliance on the plants around them.
For example, without green plants the Earth's atmosphere would not be constantly renewed. Our clothes and furniture, our food and drink, from tea and coffee to fruit juices, all originated with plants. Everything of animal origin that we buy, from shoes to the meat we eat, also depends on plants - think of the cow chewing grass and the resulting glass of milk. Only the mineral world, with its metals and plastics, is comparable as a provider of things we use every day without thinking about where they come from.
The Lost Gardens of Heligan, also in Cornwall, had initiated the plan to capture children's interest by creating a giant conservatory to house a wide selection of plants. But Heligan was not big enough, so a new site was found and architects were engaged to create the dramatic structure that would be a home to what became known as the Eden Project. The name was chosen because it symbolises humanity's harmony with nature - a bountiful Arcadia, free from need. Eden's mission is to promote understanding of this vital relationship between plants, people and resources, and the responsible management required for a sustainable future for all.
But why go to Cornwall for a school visit? The answer lies in the uniqueness of the experience - and the way in which the project brings the life of plants to children.
Already, primary school parties have visited from all over the south-west of England - from Bristol, Bath, Cheltenham and Worcester. Other schools have made the project an essential component of a local residential visit. The Youth Hostel Association has also become involved, in the provision of residential packages.
An exciting range of pre-booked workshops is offered, covering many aspects of the curriculum, stretching from science into geography, numeracy and beyond. In "A Feast of Senses", infant and special school parties can experience a sensory walk through the biomes - touching, smelling and tasting.
Children are amazed to find how many plants they have already depended on since they woke that day. As one five-year-old said: "Do you mean that chocolate comes from a plant?" The Eden Project has cacao bean trees, coffee and tea bushes, olive trees and peanut plants. Children can discover "The World on your Plate", finding that the food they eat includes stems, roots, shoots and seeds.
Older children can become "Plant Detectives", tracing plant products from their origins. In "A Survival Adventure" they can hunt the biomes for examples of the plants they need to live, using a special expedition brief in plane-ticket format sent in advance so they can prepare for the visit. They can learn how to use chocolate to spice a curry, or banana leaves to make tea bags. Workshops about using plants for dyeing and cooking are also planned.
Special workshops for all primary ages incorporate science, literacy and numeracy activities. "The Global Shop of Stories" area includes folklore stories from many cultures.
Study packs are sent out prior to each visit; for schools unable to make the journey, a virtual visit on the Internet is in the pipeline. All these activities support the teaching of sustainable development issues, meeting key targets in the citizenship curriculum.
The project aims "to promote the understanding and responsible management of the vital relationship between plants, people and resources, leading towards a sustainable future for all". This it does in a lively way, but the educational manager, Dr Jo Readman, says: "Underlying all the fun there are 15 serious messages, starting with the idea that plants are amazing. Now if we stuck those messages on a board it would be the most boring thing ever."
The dependency of human beings on plant products for food and clothing are just two of the ways in which serious aspects of sustainability are explored in a bright and breezy fashion.
In the first year of the project, in the exhibition hall that overlooks the biomes, a range of exhibits was tested, to the fascination of both children and adults. An automated kitchen scene was deprived of its plant-related products one by one-including the occupants' clothes and the cat-food.
One exhibit celebrates the rubber tree, with every product from tyres to erasers; the "Edeon" shows related films, including one explaining the complicated engineering that created the attraction.
The "glass" in this giant conservatory is made from a transparent foil (ethyltetrafluoroethylene, or ETFE). Two layers of the foil are inflated to form large hexagonal "pillows", the largest of which is 11 metres across. These provide double-glazing for the domes, while weighing less than one per cent of an equivalent pane of glass.
The equivalent of 20,000 bathfuls of water a day enters the site naturally. None of it is wasted - a drainage system filters and pipes the water to the plants, providing high humidity in the Humid Tropics Biome and also flushing the Eden Project's toilets.
On the day we visited, compost made specially from recycled waste and china-clay spoil was being spread, and mature trees, metres high and growing in giant pots, were waiting to be planted. Nozzles were turned on for the first time, to emit a fine water spray that shrouded the interior of the dome in mist. On that day the Humid Tropics Biome bore a resemblance to Jurassic Park waiting for the dinosaurs to arrive.
Fortunately, some hazards of the rainforest environment are not reproduced in the Eden Project. When she was undertaking research in South-east Asia, the project's education officer Gill Hodgson found that "leech socks" were useful to prevent these bloodsuckers getting on to her legs.
In this Cornish china-clay quarry, however, you can visit three climates without missing out on any luxuries - and the Eden Dome must be the world's only rainforest to sell excellent pasties.
For further information, contact: The Eden Project, Bodelva, Cornwall PL24 2SG. Public information line: 01726 811911; fax: 01726 811912; website: www.edenproject.com
Research the answers to the following questions: Science * What plants have you used today? What are the plant origins in buildings, food, clothing, books and toys?l How do plants come to grow in new places if they can't move around?
* What are seeds for, why are there so many and how many different ways do they get spread around?
* There are many poems about flowers. How many can you find about other parts of plants, such as leaves and trunks? Or about plants as food?
* Look for poems and stories about trees. How are trees described? Which human characteristics are they sometimes given, and why?
Research the answers to the following questions:
* How have world-wide trading disputes and even wars resulted from the use of plant products, such as spices, tobacco, even sweet peppers?
* What are the differences between the floras of different regions?
* What are the food plant staples of different countries and cultures?
Art and craft
* Cut through fruits and vegetables - red cabbage, peppers, seedy fruits - and draw or paint the cut surface.
* Make a picture of a tree using natural dyes, crushed leaves and petals.
* Some seeds are dispersed by the wind. Which tree seeds will travel the furthest? How can you show that seeds from the top of the tree travel furthest without climbing the tree?
* In The Death of Grass, science-fiction writer John Christopher imagined a world in which all the grasses (the Gramineae) were wiped out. How many food plant types would die? What proportion of human food comes directly, or indirectly, from the grasses? Why did the author predict world famine?
* What shapes cover the greatest area or volume with the least material? Investigate using different sizes and shapes of boxes. Explore, if possible, a dome shape.
* Design a garden for a sunny window-box. Think about colour, type and size of plants. The box must look good inside and out.