The global fascination with Scotland's castles shows little sign of dimming.

From Americans fulfilling a lifelong dream to TV star Alan Carr moving into his "turret era", interest in owning one has rarely been higher.

For those of us with more modest budgets, the striking looks and stories behind these structures are an enduring attraction.

Now a new archive hopes to provide a comprehensive, detailed and nationally-accessible picture of the condition of the nation's castles, their history and what their future might hold.

Richard Oram has just retired as professor of medieval and environmental history at Stirling University and is president of the Scottish Castles Association (SCA).

He said Dorothy Walker, who previously chaired the group, pushed strongly for the creation of an archive and it is an idea he was happy to run with.

Although there are other collections out there, he said none of them was "as ambitious or as comprehensive" as what they hope theirs can become.

"It's not to be a sort of a closeted-away, academics-and-professionals-only type of thing," he explained.

"This is intended to be nationally-accessible and community-supported.

"It's something that can only really gain its maximum potential by working with other people around the country."

It consists, primarily, of a series of unique images of the buildings which have been built up by a number of people over decades.

"We're either charting the decline from a lived-in building into a ruin or the gradual climbing from being a ruin back into habitation or use," he said.

"A lot of that kind of record doesn't survive in a place that most people can see it.

"They either know the building as a pile of rubble or they know the building as a private house or something of that kind and they don't know how it got from one state into the other."

Among the archive is the Alastair Maxwell-Irving collection of plans and drawings stretching right across the country from Dumfries and Galloway to the North Sea coast.

The timing could hardly be better.

"I think this is one of the really exciting things for the moment is there's this huge upsurge of interest in Scotland's castles," said Oram.

"It's always been strong, it's always been a recognised part of Scotland's culture and heritage.

"But there's now, once again, this fashion, particularly amongst North Americans, but not just North Americans, for acquiring and living in a romantic Scottish castle and a lot of restoration."

The new collection could help fuel that.

"Amongst the things that we're trying to do with the archive is also produce a body of evidence around what can feasibly be restored and what is actually beyond the point of return," explained Oram.

He said that tied in with Historic Environment Scotland's discussions around "managed decline" and how to allow a building to deteriorate but still be visited if safe and record it appropriately for future generations.

"The goal is something that gives us an up-to-the-minute, sound overview of the building as it is now with a good understanding of its historical development and the history behind that building," he explained.

"You've got places that are originally a 14th Century tower, for example, but they've been turned into really comfortable houses in the later 18th, 19th and 20th Centuries," he said.

"So it's what's been compromised, what's been added, what of the original fabric remains."

He said they hoped to "strip away a lot of the mythology" around some buildings and work with communities and organisations around the country to provide the best information possible.

All of it will be available online and also, physically, at Stirling University - and Oram said it would tell the story of the castles as plainly and simply as possible.

"It's to try and get away from some of the really starchy, confined, Secret Squirrel type of language that often descriptions of these buildings are wrapped up in," he said.

A launch of the archive takes place at Dunbar Castle on Wednesday.

"We're trying to really build interest and enthusiasm across the country," he said.

"But I think the critically important thing for us is to really push and get a better understanding of our buildings, our national heritage.

"It's something that we're hopeful will really be there to fire up the enthusiasm of the broader public and all the people that we know around the country that are absolutely passionate about castles."