We visited the 'hot one' first. You follow a path that steadily climbs up the dome through various plant displays laid out in countries along with native style huts and waterfalls. It is hot and humid in here but the views from the top are worth it. Some of the plants and flowers are beautiful and there are interesting displays on palms, bananas, and coca.

In the 'cooler' dome, it is more a Mediterranean-style complete with courtyard style gardens, lemon trees, peach trees, and also a lovely display of South African plants. The core is a new building that is an educational building with some interesting displays for children in particular and was opened officially by the Queen 2 days after we were there.

There is also an extensive shop selling all kinds of plants, flowers, books, foods, and local produce as well as several cafes around the site.

If you are feeling brave you can take the zip wire across the site but it's just as fun to watch the brave souls!

Well worth the money to visit and if you are a UK tax payer you can opt to sign up to gift aid which also entitles you to upgrade your ticket to a free annual pass which is great if you are local, or planning to return to this area within in the next 12 months.

The Core only opened this summer and has quickly become a favourite with the hundreds of thousands of visitors to Eden. The Core is built to an extraordinary design. Other than the uprights, not one timber is straight in this truly iconic structure. The roof is built to the natural growth blueprint of a flower and took over 1,000 cubic meters of Swiss spruce from sustainable forests to create.

There are 335 major beams and 34 vertical uprights, all finished to the highest degrees of workmanship by master carpenters. The beams required so much “bend” to create the roof that new techniques were devised to essentially glue pieces together, both laterally and longitudinally, to enable the architects to acquire the “bending” necessary for this section of the building.

The roof itself is finished with copper, sourced from the Burgham Canyon mine in Utah and painstakingly fitted together again by local master craftsmen.

The interior is crisp and clean and has several interactive displays as well as film rooms where projectors show the conception, planning, building, and completion of Eden. The centre basically examines the roles that plants play in all our everyday lives, including medicines, fuels, building materials, filters, latex, and, of course, foodstuffs.

Recently, a plan has been devised to install what will be the largest single piece of sculpted stone since the time of the Egyptians as centrepiece to The Core. This stone, in keeping with local tradition, had to be Cornish granite. A suitable piece was found at the De Lank mine near Bodmin, where it took 4 months to cut away from the enveloping terrain with thermic lances. It was finally “released” with dynamite. It’s been estimated that the stone weighs around 170 tonnes and is at least 280 million years old.

A monster 750 tonne crane was brought in to lift the stone free, and work is ongoing as I write, with the sculpture due to take pride of place in 2006, a perfect excuse to return next year, I feel.

These three biomes are smaller than their Tropical counterpart but no less fascinating. They are situated to the right of the restaurant and are again accessed via sliding doors. The interior is markedly cooler than then other side, as you would expect, and the initial sensation is that of the smells of the Mediterranean: geraniums, hibiscus, bouganvillea, and wild herbs.

There are 19 principal exhibits or areas inside here, numbered from W.01 to W.19: Introduction to the Warm Temperate Regions, The Mediterranaen Basin, South Africa, California, Introduction to Crops and Civilisation, Fruits of The Mediterranean, Cork, Peppers, Alliums, Citrus, Grape Vines, Aubergines, Tobacco, Lesser Known Grains, Cut Flowers, Sunflowers, Olives, Cotton, and Perfume.

The Mediterranean exhibits are especially realistic, featuring beautiful urns of flowers, entire hillsides cloaked in maquis, olives trees and presses, and an area dealing with all types of citrus fruit. The perfumed air is simply unbelievable, a heady mixture of myrtle, sage, juniper, broom, and rosemary. I really do feel as though I am back in Greece. These wild herbs, intermixed with dwarf fan palm, prickly oak, and bay, combine to form exactly the rough maquis covering that Greek, Spanish, and Italian mountainsides are renown for.

The Californian exhibit features naturally enough all types of cactus along with scrub oak, buck bush, and toyon, all in an authentic semi-arid setting and built around a ranch house. The South African exhibit has a huge variety of its indigenous plants, representative of the richest density of plant life to be found on Earth. Heathers, lilies, orchids, and irises form the centrepiece here, growing as majestically and fully fragranced as they would do in their natural habitat.

That is precisely what Eden is about: not to try and grow these plants in an alien climate and environment and hope for the best, but to recreate exactly the soil, drainage, temperature, rainfall, and humidity conditions that cause them to thrive in their native countries.

The Temperate biomes really only take an hour to explore, unless you are a keen flower person, but some of the smaller exhibits, such as cotton and perfume, are equally fascinating. The Pepper and Chillies areas are also worthy to stop awhile. Real chillies and capsicums of every variety are growing well here and are listed according to strength on the Scovill scale.

Having seen the interior of both sets of biomes, I now set off across the gardens outside to the new Information and Education centre, known simply as “The Core.”

Both the Tropical and Temperate biomes are accessed via the huge restaurant area that sits between them both. The Tropical Biomes are to the left. You enter via a steamed-up sliding door that is dripping with condensation. Outside today it is barely above freezing; in here it’s at least 20C, making the removal of the leather jacket essential.

Guides are available at £2 per head, but I decide to go it alone. A pathway snakes its way around the inside of this enormous greenhouse, taking you past all the exhibits as well as, of course, the huge plants that are on display. The size of this place is staggering: 240m long, 110m wide, and over 50m tall. It has been positioned to make the most of the natural contours of the clay pit, although it didn’t stop there. Tens of thousands of tonnes of soil have been placed inside to landscape the interior, providing a walkway that twists and turns almost to the very top of this monumental structure.

The waterfall that cascades from the very top is entirely natural and is the water that drains into the pit from the surrounding land, albeit has been channelled to this one specific point to provide a spectacular centrepiece. The air resounds with the chirping of the bird population that has been encouraged to make the biome their home. There are enormous palms, swaying ferns, gigantic cacti, banana trees, coconut palms, and so much more.

The various exhibits are numbered from H.01 to H.25 and are Introduction to the Humid Tropics, Tropical Islands, Malaysia, West Africa, Tropical South America, Crops and Cultivation, Cola, Chewing Gum, Rubber, Timber, Cocoa and Chocolate, Palms, Rice, Coffee, Tropical Displays, Sugar, Mangoes, Bananas, Tropical Fruits, Bamboo, Pineapples, Pharmaceuticals from the Land, Spices, Cashews, and Tropical Dyes.

Scattered throughout the various exhibits are traditional dwellings of the indigenous peoples, reconstructed to a high and authentic level using traditional materials. These include a Malaysian rumah kampoor, an African rondavel, a bamboo house, and a Sri Lankan spice stall. Also on show are “Aziza,” wooden black spiritual figures said to know all the secrets of the forests.

After an hour or so, you reach the summit of the pathway. Down below you, the true extent of the biome can be seen, along with lily ponds, streams, and waterfalls. The only place loftier than this is the metal catwalk that leads to the very apex of the biome, where enormous panels can be opened to regulate the temperature and humidity. It is a truly fantastic viewpoint, and I linger for 15 minutes or so just to savour the magnificence of the spectacle before starting to feel the effects of the humidity and stifling temperature.

This part of Eden accounts for around 75% of the entire garden area and is loaded with many modern sculptures and displays throughout its walkways. From Exhibit 0.08 to 0.23, it details Plants for the Industries of the Future, Lavender, Plants and Pollinators, Cornish Crops, Beer and Brewing, Tea, The Education Centre, Eco-Engineering, Hemp, Hidden Crops from The Andes, Plants for Rope and Fibre, Steppe and Prairie, Plants for Fuel, Plants in Folklore, Biodiversity in Cornwall, and, finally, Minerals, Metals and Mines.

Nonfloral displays include the wonderful “Bombus the Bee,” a huge bumblebee constructed by Robert Bradford in vivid colours; the traditional hop-poles in the Beer and Brewing section, carved by Reece Ingram; the Hemp Fence; the Metal Giant by George Fairhurst; The “Industrial Plant” by David Kemp; the Story Pavilion; and, last but not least, the amazing WEEE Man, built entirely of household electrical items from fridges to mobile phones.

As Eden itself was engineered from an old clay pit, part of the interior has been left as it was found, with huge boulders of granite, dry stone walls, and rocky terrain, allowing the bird, insect, and reptile population that had colonised the pit after its fall into disuse to continue on as they had done, building nests, raising young, and thriving in what is now still a wild area, albeit under under close stewardship.

This part of the gardens can easily absorb you for 2 or 3 hours as you suddenly discover a pathway that you hadn’t noticed before. The sculptures and other pieces are so at one with the plants, it almost becomes an adventure playground for adults. The delight of finding a 5m-long bee around the corner or a simple xylophone constructed of Cornish slate adds to the enjoyment of this superb walk of fact-finding and discovery.

A particularly entrancing object is The Cloud Chamber. This is a slate built domed hut with a thick piece of glass embedded into a hole in its apex. This throws a reflection of the sky onto a flat stone surface inside the chamber. It is extraordinarily relaxing to sit there for 10 minutes watching the clouds scud by, although you wouldn’t have this time to yourself in high season.