King Abdullah International Gardens, Riyadh, Saudi Arabia

Hailed as one of the new 'seven wonders of the world' the King Abdullah International Gardens (KAIG) in Riyadh, Saudi Arabia is a vast futuristic botanical garden and leisure complex of 160ha, which is to be constructed in the desert just outside the Saudi capital.

The front entrance of the scheme will be called the 'Gathering Plaza' and currently could be in one of three places depending upon space on the site. The main building will be a 20-acre complex consisting of two interlocking crescent structures enclosing seven different sections containing flora from distinct botanical periods.

The garden, which has been designed by UK design and planning, architects Barton and Wilmore (after an international design competition) will be enclosed by two interceding crescent shaped 'domes' similar in structure to the 'Biomes' used in the Eden Project in Cornwall.

The domes (forming one of the worlds largest Teflon structures) and the related infrastructure will not only have to maintain and control the environment for the various plant species but will also have to act in a sustainable fashion by collecting rainwater in the winter months, making use of solar power and by using wind turbines.

The project was commissioned by the Mayor of Riyadh and has been largely funded by contributions from businesses and individuals in the city of Riyadh. The project, when completed, will provide a new attraction for the city as well as being a place of education and scientific research. The King Abdullah International Gardens, started in 2007, are due to be completed by the spring of 2010.

KAIG CONTRACTORS

Barton Willmore as architects will undertake the $170m project in a joint venture with civil engineers Buro Happold, sustainable development design group Emergy and the Natural History Museum (the Eden Project are also acting as advisors).

One of the central tenets of the project is sustainability and this will mean that the scheme's power requirement will be provided primarily by solar power, supported by accessory wind turbines and Combined Heat and Power sources (CHP).

Rain, which falls intermittently in the late winter months, will be harvested and collected in underground reservoirs before being cleaned, used for irrigation and then recycled.

The garden temperature will be controlled by building high domes (roofs) into the Teflon structure. Some of the domes will be more than 120ft high and this will encourage hot air to rise trapping the cool air at the bottom.

The load on the air conditioning will then be much lower and it will be able to keep the temperature regulated more easily without wasting energy.

PLAN AND BRIEF

The joint venture brief is to research, procure and build the scheme, planning and constructing a range of scientific, water, play and display gardens in the broader scope of the whole site.

Nick Sweet the project director and partner in charge of urban design at the Barton Willmore London office said: "When we read the brief, we decided to recognise the irony of producing proposals with a strong educational message on sustainable developments in the heart of the world's principal oil-producing nation.

"In this day and age, we are all, to a degree or another; fearful of the rapid changes in climate change occurring in the world and many are uncertain about how to respond. We wanted to use the scheme to tell the story of a single piece of land through time. It might be a desert now, but there was a time when rivers flowed here and forests grew."

GARDEN CENTREPIECE

The centrepiece of the proposal is a 20-acre paleobotanic building (containing primitive plant species) formed by two interlocking crescents that accommodate a sequence of seven controlled environments.

Each of the specialist environments in the gardens will allow visitors to travel through a period of time and actually recreates some pre-existing ecosystems based on actual environments which would have occurred on the site throughout time (Pliocene, Cenozoic, Cretaceous, Jurassic, Carboniferous, Devonian, garden of choices).

Each will be presented as a complete environment, including those species from each which survive to this day and accommodating the remnants and descendants of species that have been lost.

The concept for the gardens is that they be presented as a time line, which leads the visitor to the wadi garden, the large central space enclosed by the dual crescent structure will be developed to emphasise the existing desert ecosystem, that will use only the species that are native to the local area. After nightfall the wadi garden will become the 'Garden of the Moon' and there will be special lighting to emphasise it features for evening visitors.

The final enclosed garden within the crescent building is the 'Garden of Choices', an educational space, which explores and explains the choices human-kind is still able to make and which have the potential to preserve the environment of the planet for future generations.

OTHER GARDENS

The gardens will also provide much more than a botanical history with facilities to show visitors the beauty of the world around them and what they can do to preserve it. The gardens three goals are to inform, to educate and to entertain.

The Scientific Gardens situated to the south-west of the main complex will include: the water gardens, the physic garden (promoting Islamic medicine and teachings), the aviary (with a multitude of exotic birds free to fly around), the maze garden (with a low-wall maze fashioned in the native rock), the garden of light and sound (a special walled garden) and the grotto (inside the grotto building with a theme of water preservation).

The atmosphere of the gardens is expected to be developed as a fun place and not be exclusively for education. The complex will therefore also feature a cliff walk, extensive seating, and picnic areas. To extenuate the views there will be look-out watch towers.