In a crater the size of 30 football pitches, an amazing structure has grown. Two glass and metal biospheres, like habitats from another world, house the largest indoor tropical rainforest in the world.
If you landed on an uninhabited planet like Mars, how could you make it suitable for life? You’d be starting from scratch: no buildings, no plants, just a dusty wasteland. That’s the kind of challenge faced by the engineers at the Eden Project.
They transformed an abandoned clay quarry in Cornwall into thriving living habitats called biomes that now attract visitors from all over the world. Let’s find out how they did it – it might help you build your own world.
The designers tried to recreate a mini-Earth inside the biomes. There’s a huge rainforest biome (hot and steamy) and a Mediterranean biome (hot and dry). More than 2 million different plants live at Eden, not to mention a few animals.
The quarry had been supplying china clay to make porcelain cups and saucers for 160 years. When it was abandoned, it left behind a craterous eyesore. It took nearly 3 years to transform it into the Eden Project.
A record-breaking 230 miles of metal scaffolding was used to build the biomes. The outer layer is made of hexagons that neatly fit together. The largest is 11 metres across – nearly as long as a T-Rex!
Abseilers install the plastic that covers the biomes. Several layers are sealed and inflated to create a large cushion of air. This insulates the biomes, keeping the plants warm in winter.
Living in Harmony
Part of the aim of the Eden Project is to educate people about how we can live with each other and the living world to build a better future and protect planet Earth. Core to the vision is inspiring people to use Earth’s precious resources sustainably so they don’t run out.
Eden has solar panels on its roof. They absorb sunlight and transform it into electricity, which is used to power machines and lights. The Eden Project gets as much of its energy as possible from renewable sources like the Sun and wind.
Let the Light In
Let the Light In
Seen from above, the roof looks like the head of a sunflower. The spikes are actually windows that open. Designing buildings that let in lots of natural light reduces how much electricity will be needed for electrical lights.
This giant sculpture represents the amount of Waste Electrical and Electronic Equipment that the average household throws away in a lifetime rather than recycling. His brain is built from computers, his ears are satellite dishes and his bones are mobile phones and lawnmowers.
Loads of water is needed to irrigate the plants at Eden – and to flush the loos! Huge ducts collect rainwater from the roof. Two-thirds of the water needed comes from water collected on site, saving money and energy.
The rainforest biome is the world’s largest conservatory – 55 metres high and 250 metres long. The air inside is kept at varying temperatures, between 35°C (hot!) and 18°C (mild). Rainforest plants need different temperatures to grow successfully.
The rainforest biome helps visitors understand how important rainforests are, providing us with many resources and home to many different animals.
This viewing platform is 50 metres high. It allows visitors to see all 2000 tropical plants growing here, including bananas and papayas we can eat, red stinkwood that gives us a medicine to fight cancer and tall trees from which we get timber.
The transparent plastic hexagons let in lots of light, which the plants need to make food. The plastic pillows are much lighter than glass and if they are damaged, they won’t smash into pieces – they can be repaired with just a bit of sticky tape!
Some of the plants here grow really tall, really quickly. Bamboo can reach a height of 35 metres. To stop it growing through the plastic roof, it’s trimmed back regularly by a gardener lifted up on a cherry picker.
Bamboo is a really useful plant because its hollow stems make it strong and light. It has been used to build houses, bridges and even a bike! It can be used as fuel and the young shoots taste pretty good as well.
The plants inside this biome come from all over the world and grow in all shapes and sizes. However, the plants inside the rainforest biome have one thing in common: they love water! In a real rainforest, it rains every day.
Here at Eden, the plants are watered three times a week. Other plants live directly in water, such as the lilies in the lily pond.
Plants that grow in soil absorb water through their roots. They release it back into the air through tiny holes in their leaves called stomata. The air inside the biome becomes saturated with water, making it very humid and sticky.
The Santa Cruz water lily from South America grows in one of the biome’s ponds. The leaves grow up to 2 metres in diameter – bigger than a person! Hollow veins in the leaves give them buoyancy so that they don’t sink.
The lily flowers are enormous too when they open – up to a metre in diameter. They open at night and give off a scent that attracts a beetle pollinator. The flowers turn pink the following day and lower back into the water.
Animals live in balance with the plants and are part of the food web. Frogs and lizards eat pests that feed on the plants. Using this “biocontrol” means that gardeners don’t have to use chemical pesticides.
The Mediterranean Biome
The Mediterranean Biome replicates the landscapes of California, South Africa and of course the Mediterranean. The climate inside the biome is hot and dry in the summer. Many of the plants here can survive in poor, thin soils with little water.
The flowers are highly scented and brightly colored to attract pollinators.
Many plants in this biome, such as cacti, have adaptations to help them live in dry conditions. Leaves and stems have a waxy coat that seal in moisture. The leaves are small, sometimes just spikes, which reduces the amount of water evaporating from their surfaces.
The grapevine here grows high up the side of the biome. In the wild, grapevines can grow up to 35 metres long. Grapes can be eaten fresh, or dried as sultanas and raisins. Grape juice can be drunk or used to make wine.
These sculptures tell the story of Dionysus, the Greek god of the wine harvest. He started drinking grape juice but turned to wine. He is joined by his female followers, the Maenads, playing their instruments. Their name means “the raving ones”!
The Japanese Garden
Not all of the 2 million plants at Eden grow inside the biomes – most are in the outdoor gardens. There are miles of paths that take you all over the old quarry that is now transformed with ornamental flowers, allotments and ...
... plants to stimulate your senses, as well as plants for fuel, medicine and materials. There are many mini-gardens, such as the Japanese garden arranged to represent different parts of the world.
To model how plants grow in the wild, the gardens are planted in layers. Tall trees make up the canopy layer, shorter shrubs are in the understorey, and these ground-cover plants have adapted to grow on the forest floor where there is little light.
The Green Team
Around 400 staff work at the Eden Project full time. The Horticultural team, known as the Green Team, looks after the plants; the Education team communicates how we can live in harmony with the natural world; and the Hospitality team makes sure everybody is fed.
In Autumn, all of the leaves need to be cleared up. They don’t get thrown away but are instead squashed into enormous biodegradable leaf bags. The leaves rot and turn into rich, nutritious compost. This compost is added to the soil to feed the plants.