FIVE years ago, the Duchess of Northumberland announced plans to turn a 12-acre site into the most magnificent public garden created in Europe in the last 100 years. The spectacular project has now opened to the public for the first time.

IN 1775, the celebrated landscape gardener Capability Brown redesigned the grounds at Alnwick Castle. Now Jane Percy, the Duchess of Northumberland, is building on his famous legacy to create what some are already calling the English Versailles.

She says: "No gardens of this scale and ambition have been undertaken in Britain during this century. It is not a slavish recreation of the past but a garden for the 21st Century. " With more than 65,000 plants and spectacular water features constantly recycling 250,000 gallons of water, the garden is hugely ambitious. At £14m, the cost is stupendous. The Percy family is providing around £5m, while the rest is coming from corporate sponsorship and European funding.

Jane Percy became the Duchess of Northumberland in 1995 when her husband, Ralph, inherited the title following the unexpected death of his brother. A keen gardener, she soon spotted the potential of the castle's grounds and set about making her vision a reality.

It has not been easy. Many conservationists opposed the scheme and, earlier this year, the project attracted adverse publicity when the town's water supply was, temporarily, turned off. But the Duchess' persistence paid off and the garden welcomed its first visitors on Monday.

Sadly, last year's harsh winter put construction behind schedule and the centrepiece of the garden, the Grand Cascade, still resembles a building site. When it is completed, probably by the end of next month, visitors will be greeted by thousands of gallons of water rushing towards them like a tidal wave. Water is the central theme of the garden and emerges throughout, in jets and fountains.

As a mother of four, the Duchess is keen the garden should be fun for children. She wants to avoid her own childhood experiences of garden visits when she found the most exciting part was the visit to the giftshop. One pool at Alnwick sends bubbles up to the surface, creating the impression that there are crocodiles or monsters living underneath.

The garden will also appeal to serious plant lovers. It was designed by the celebrated Belgian father and son team Jacques and Peter Wirtz, whose work includes the Tuileries Gardens in Paris. The Alnwick Garden was their first British commission and they were conscious of the history of the site. Peter says: "We saw our proposals as totally innocent and non-aggressive, very respectful of the site and of what was reusable from the past."

Their Ornamental Garden has been created on the site of an 18th Century formal garden, which was abandoned after the 'dig for victory' campaign during the Second World War left it in ruins. Invisible from below, it is only accessible by climbing up through the arcade of hornbeam trees flanking the cascade.

It provides a complete contrast to the garden below, with its curvilinear green architecture. Here the visitor finds clipped hedges and gravelled walks. Flowers alternate with vegetables and fruit trees, while the perimeter is a wide herbaceous border.

The flower collection includes oriental poppies, peonies, aster and the Alnwick Castle Rose, specially created by David Austin Roses and unveiled at this year's Chelsea Flower Show. They all flower at different times of the year, creating swathes of colour and filling the air with perfume. The beds have also been planted with soft fruit.

Ian August, project director, says: "The garden will be open 364 days a year so we have had to create one for all seasons."

round 250,000 people are expected to visit each year, but Mr August believes it will be more. He says: "We are creating something that has never been seen before in this country. It is going to be an enormous attraction both for people in this region and much further afield, as well as a boost for the local economy.

"One of the secrets of its success is the Duchess' involvement right from the start. It has always been her vision."

Since construction work began last year, one of the regular visitors to the garden has been Ground Force's Charlie Dimmock. She is filming a TV series about the project called Charlie and the Duchess to be screened later this year.

The Alnwick Garden is a registered charity. Visitors can become a Friend of the Alnwick Garden for an introductory rate of £10 for individual membership or £25 to become Family Friends. It is open from 10am-4pm. Admission, £4 adults, £3.50 students and OAPs, children under 16 free. Call (01665) 510777 for more details