Gwrych Castle, with its crenellated towers and turrets peeking out of forested hillsides, is the picture of gothic fairy-tale grandeur.

But the castle, set in 40 acres near Abergele in north Wales, with sea views from its battlements, is a Georgian folly rather than the stronghold of a medieval warlord. Built in 1819, it is now uninhabited and crumbling, and is on the market for £1.5m.

News of the forthcoming sale is welcomed by heritage groups who have long lobbied to safeguard the future of the castle — which they view as one of Wales’s most important buildings — but the price tag is not. The Grade I-listed property, whose roof has fallen in, needs £2m spending on it just to make it watertight. Renovation costs are estimated to be so high that a feasibility study commissioned by the Gwyrch Castle Preservation Trust came to the conclusion that the property has “nil value”.

The trust is launching an appeal to raise the £2m. If it can prove it has enough funds to cover the work, the local authority could compulsorily purchase the castle and pass it on to the trust. Mark Baker, secretary of the trust, says: “A change of ownership could save the castle. But it is completely derelict and will take £4m- £5m to restore it.”

Baker, 21, was a 12-year-old schoolboy when he set up the Friends of Gwrych Castle. “I remember the stained-glass windows vividly,” he says. “The glass is all smashed now, and no records exist so the windows can’t be rebuilt.”

Designed by Thomas Rickman, the mock castle was built by Lloyd Bamford-Hesketh, a wealthy Lancashire industrialist. After he died, the castle went to his son, then to his granddaughter, who bequeathed it to the Prince of Wales, later Edward VIII, who turned it down, so the castle went on the market.

The 1946 house-sale particulars reveal false bookcases in the vast library and note an imposing oak-panelled hall; the 2006 brochure highlights the danger of visiting the site.

In its heyday, the castle had 120 rooms including 28 bedrooms, an enormous dining room, billiards room, music room, library and eight bathrooms, as well as an ice house and a dynamo and battery room that provided a private electricity supply. It was requisitioned during the second world war and sheltered 200 Jewish children of the Kindertransport. By the 1970s, the castle had become something of a medieval theme park attracting more than 10m visitors.

Its owner, a Californian property developer called Nicholas Tavaglione, bought the castle for £750,000 in 1989, heading up a syndicate of international buyers with a plan to turn it into an opera centre in memory of Richard Burton, the actor. But it was besieged by vandals who removed fireplaces and chipped away at the 52-step marble staircase. Plans to build holiday chalets in the woods and turn the castle into a hotel and casino also failed to materialise.

So what is the future now? “We have had inquiries from individuals who are looking to restore or at least partially restore the castle,” says Christopher Dibb of Beresford Adams. “But that it could be developed into flats or holiday lets is not beyond the realms of possibility.”

Gwrych Castle goes to auction on June 2 with a guide price of £1.5m at the New Connaught Rooms in London; Beresford Adams, 01492 875 576, www.bacommercial.com; www.gwrychtrust.co.uk

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