Chris Lloyd is awestruck by the remarkable Edwardian Rock Garden in Aysgarth, which is now open for public viewing for the first time in its history thanks to huge efforts on the part of its new owners.

THERE is a thing on the corner of the road sweeping out of Aysgarth. It is large and dark and brooding, and totally out of place amid the verdant pastures and sunny green slopes of Wensleydale in early summer.

It has stood on the corner since 1906, and passers-by have paused open-mouthed by the metal railings which seem to pin the thing in to prevent it from expanding and taking over the whole of the dale. From the safety of the roadside, they gawp at its gargantuan enormity, asking what could possibly lurk within its towering darkness, and wondering who could ever build such a thing in the first place. And why.

For much of the last century, the gawpers would be disturbed from their meditations by a frantic tapping on a pane in the house behind them, and a face at the window would be demanding that they looked no more and moved away.

Once that face herself had passed away and her family died out, Mother Nature turned on the thing behind the iron railings. Ash and sycamore trees started growing from its terrible heights; brambles roamed their long and prickly fingers over its craggy features and nettles gained stinging footholds in its nooks and crannies. Over the decades, they covered its rugged edges with smooth leaves and hid its dark, looming presence with their greenery.

But now, with the help of grants of nearly £25,000, the thing has been cleared of its overgrowth and is, for the first time in its history, open for public viewing. In fact, it positively welcomes visitors.

"I call it my not-so-private private rock garden," says Angela Jauneika, who owns the Aysgarth Edwardian Rock Garden with her husband Peter. "It really should be seen."

It is extraordinary, one of only a handful of gardens in the country which is Grade II listed. Whether it is beautiful is a matter for debate once you've had the full tour, but it is definitely arresting and awe-inspiring. Utterly extraordinary.

Through the gate in the railings you go and duck beneath a rocky lintel which wants to scratch the skin off your scalp. You are confronted by a towering Alpine peak with water pouring down it and plunging into a pond way beneath your feet. Up the hillside you go, marvelling at the plants clinging to the rocks and wondering however Angela climbs to the top to tend them, and round a corner into a dank, dark dell where ferns flourish.

"Even at the height of summer, it is always cool in here with the north facing aspect," says Angela.

The limestone rocks crowd in claustrophobically as the path becomes a mountain pass. Who knows what is moving on the heights above your head, but an ancient spreading juniper tree protects you from their sights.

Round a tight corner and you emerge back into the sunlight. A little turfed area which was once a vegetable garden, and the dale rising gently before you. It is time to explain...

James Backhouse was born in Darlington in 1794, into the famous banking family. He was initially apprenticed to a chemist in the town but, as a Quaker, had a profound love of nature. In 1812, he went on his first expedition to Scotland, collecting rock plants.

Inspired, he gave up the drugs and bought a nursery at Acomb in York, which he filled with Alpine specimens collected on his expeditions to Austria.

Although James died in 1869, his company flourished as it became fashionable to create Alpine corners in the grounds of stately homes. The company's best-known construction is a 30ft high replica of the Matterhorn mountain in a garden in Henley - the late Beatle George Harrison was its last owner.

Meanwhile, in Aysgarth, Frank Sayer Graham (1859-1946) was making money. He farmed silver fur rabbits in his purpose-built warren at Lady Hill just outside the village. He could kill a rabbit in Aysgarth at 9am and it would arrive, frozen, in London on the 4pm train. From there the fur would go to the great fashion houses of Europe - he is said to have supplied the last tsar of Russia with silver fur for a stole.

Frank was an illegitimate son in an age when such things mattered, and when his father died he moved back into his childhood home of Heather Cottage on the corner in Aysgarth. He had arrived.

He turned the cottage into a beautifully-detailed Edwardian Arts and Crafts home and then turned his attention to the paddock out the front.

In 1906, he commissioned James Backhouse and Son to build a gigantic rock garden on the roadside.

"Whether it was because he was illegitimate, trying to prove something, I don't know," says Angela, "because he could have put his rock garden down out of the way behind the house where no one could see it."

It took the company eight years to build, dragging the waterworn limestone off nearby Stephen's Moor and carrying it down the dale on a low horse-drawn cart. Quite how the stones were then lifted to the top of the Alpine peaks is anyone's guess.

"Most of them are laid together but there are places which have been packed out with stones and lime mortared," says Angela.

But no one was allowed inside to see what had been created. "Locals who remember Frank all say they were not welcome in his garden," says Angela. "People who were then children recall his wife rapping on the windows of Heather Cottage if they so much as touched the railings."

After Mr Sayer Graham's death in 1946, successive owners of the rock garden fell out of love with their giant as it disappeared beneath brambles and saplings. It was going to be demolished in 1988, only for English Heritage to list it. The then owner filled it with garden gnomes dangling their fishing rods from tops of peaks and chopping their logs by the pool.

"Locally there must have been a large population of teenage lads with air rifles," says Angela, "because we keep finding decapitated gnomes everywhere."

The Jauneikas stumbled upon the property in 1998. "We were following the dream," she says. "We both worked in computers, we were starting a family and we were asking ourselves 'where do we want to settle down'.

"We did a lot of walking and loved the Dales and decided this was the place. We were looking for a farmhouse but the estate agent kept sending us the details of this place. The house was too new for us and we didn't know anything about rock gardens, but we called in on our way from viewing another property, and we fell in love with it.

"We didn't have a clue what we were taking on."

The plan was for Peter to continue with the computers while Angela did an upholstery qualification to further her hobby of antique furniture while running a B&B while looking after the two children.

But the rock garden loomed over them. The upholstery fell by the wayside; the B&B went on the backburner. The rock garden took over their lives.

"We spent a year trying to clear some trees before realising we were fighting a losing battle and not going about things the right way," she says. "I took a step back and decided it did need saving. I started a two-pronged attack: researching its history and looking for grants.

"There's lots of money out there, lots of grants, but it's quite soul destroying trying to get it. After all, who's going to give money to an individual to do up their garden?"

After three-and-a-half years of searching, the Yorkshire Dales Millennium Trust funded by the Heritage Lottery Fund offered 80 per cent of the £25,000 required. The Royal Horticultural Society and NatWest also helped out, but the Jauneikas have funded most of the balance themselves.

Specialists with cranes were called in to clear the garden. "There were some interesting ferns left behind, some ramonda and a juniper tree, and some beautiful cushion saxifrage, but not as much as you would think," says Angela.

So specialists in Alpine plants were called in. "I have always been interested in gardening, but not knowledgeable," says Angela. "We had a walled yard in Staffordshire with lots of pots. When the plants died, we chucked them out and put others in."

Now, the job is complete and open to the public (in return for a small donation).

"I am always restoring bits of old furniture and now I have done a rock garden," says Angela matter-of-factly, but it is clear she is besotted by the monster over the road that she has brought back to life.

"The first stage is learning to cope with what we have now got," she says. "I have got to get through a whole year to see how the weeds come up and how the plants survive and to find out how time-consuming it is going to be."

It is clear, though, that she's planning to be tending the giant for longer than a year.

"In my dreams, I want to get the rear back to Edwardian vegetables, finding seeds of vegetables that they grew in those days," says Angela, 38. "But maybe that's for our retirement."

* The Aysgarth Edwardian Rock Garden is being officially opened on July 5 by Eric Robson of Gardeners' Question Time, but visitors are welcome before.