Prior Park Gardens, Bath by Simon Heptinstall

Locals predicted a monumental flop when Britain's largest conservation charity opened the gates of a beautiful landscaped garden on the outskirts of Bath without providing any car or coach parking.

National Trust officials claimed that the no-cars experiment at Prior Park was a chance to "prove a green transport strategy can work."

The Park – which is part of the World Heritage Site – has now been opened for more than ten years and Trust officials are delighted that the doubters have been proved wrong. Already they've clocked up hundreds of thousands of visitors to the Park. All of them have abandoned their cars in the city centre and walked, cycled, taken a taxi or public bus.

The restored 18th-century gardens at Prior Park on the outskirts of Bath opened 1996. When a large sign at the entrance was erected saying: "Thank you for using public transport..." it seemed to be more in hope than gratitude.

At the nearest comparable Trust property, Dyrham Park on the northern side of Bath, there’s a large car park as you drive into the grounds.

To reach Prior Park, however, normally car-bound British visitors have to take the numbers 2 or 4 buses from a shabby bus stop near the Bath rail station or walk more than a mile up a steep hill.

To many National Trust devotees, however, the lack of a car park seems to evoke a wartime spirit of sacrifice in the face of the mysterious car park rationing.

"It's a marvellous system," one brave elderly lady visitor told me, having stepped off the bus in the rain. "It's no trouble at all," another pensioner couple said, despite waiting outside the locked gates for 20 minutes because their bus was early.

"We're absolutely delighted," said Celia Mead, Trust spokeswoman. "We've spent a lot of time and money persuading people to use public transport and it appears to be working."

Following its half a million pound restoration; Prior Park features a circular path round the 28 acre Capability Brown landscaped gardens. The highlights are sweeping views of Bath, a stunning Palladian bridge across an ornamental lake and impressive close-ups of Prior Park house.

This was once home of the philanthropist quarry owner, Ralph Allen, who financed much of the building of Georgian Bath. It is now a private school, closed to the public.

Residents of the Priory Close estate opposite the Park campaigned angrily against the opening of the car park-less Park. They feared their roads would be jammed with visitors' cars.

Tom Bowden, chairman of the residents’ association, resigned from the Trust in fury over the lack of parking. "I was very rude to them," he says. "They got themselves into this state of mind that they weren't going to have a car park whatever anyone said.

"Now I don't mind saying I was wrong. I'm amazed to see very elderly people walk all the way up the hill to Prior Park. It has opened my eyes."

The Trust's policy is to reduce attendance by cars at all their attractions from the present 90 per cent to 60 per cent by 2020.

Nevertheless, Trust officials did find room for some car parking at Prior Park. Tucked away at the bottom of the Park, behind trees, is the staff car park.