Coinneach Maclean, a former Deputy Chief Executive of the National Trust for Scotland and academic, says the country is squandering an irreplaceable heritage while making billions of pounds from it. 

Even Jon Snow was at it.

Channel Four news had come up to the Highlands before the general election to examine the SNP surge in the north. As part of his package, the estimable broadcaster went to Culloden, which he described as, "The scene, 270 years ago, of the last great battle between the English and the Scots."

Had his researchers gone in to the National Trust for Scotland's (NTS) impressive £10 million visitor centre, they would have learned that the battle in April 1746 was most definitely not a battle between the English and the Scots. The interactive exhibition debunks the notion it was such an engagement, underlining it was a civil war which threatened to engulf the whole of Britain. There were Scottish soldiers and Gaelic-speaking clansmen on both sides, as there were Englishmen.

But the myth about Culloden being a Scots/English conflict endures, despite the efforts of the NTS and others. It is certainly not the only chapter of Scotland's story to be popularly distorted, or indeed that of the Jacobites.

Few will know, for example, that the MacDonalds of Skye were officially Hanoverian in the 1745 Rising and that they were involved in the subsequent search for Bonnie Prince Charlie when he went on the run. Even fewer that it was one of these same MacDonalds who was the architect of the prince's escape in what was to become one of the best-known boat trips of all time.

According to Alistair Maclean and John S Gibson in their book A Summer Hunting a Prince: the Escape of Charles Edward Stuart: ''It was to the Prince in the cave behind Beinn Ruigh Choinnich (in South Uist) that a messenger now brought a surprising proposal from none other than Hugh MacDonald of Armadale, who commanded the MacDonald Militia company, ostensibly hunting for him in South Uist. This was to the effect that the Prince should be disguised as a woman and ferried over to Skye as maid servant to Flora MacDonald, a young gentlewoman of the Milton family of South Uist who was also Armadale's step-daughter.''

So it was that the cross-dressed prince and his party left from the south side of Loch Uisgebhagh on Benbecula's east coast to sail over the sea to Skye and into the pages of romantic history.

One of the co-authors, the late Dr Alistair Maclean, was a renowned GP on South Uist for decades after the Second World War. The brother of Gaelic poet Sorley, he would talk at length to his older patients in Gaelic of the oral tradition of the islands.

One man, Duncan MacDonald of Peninerine, gave him the story of another of the occupants of the boat that left Loch Uisgebhagh, one Neil MacEachan. An important Jacobite agent who was to go into exile with the prince, his son was Napoloeon's Marshal MacDonald, later created the First Duke of Taranto.

Maclean wrote that this was all new to him, and when he asked his source about the more famous Flora MacDonald "... something of the magic had gone and the flame of Duncan's enthusiasm diminished".

It became clear to Maclean that his "schoolboy history" of Flora MacDonald had hidden a more important story which had not been in his textbooks or other historical works, but had been passed down through generations of islanders.

So much of that oral tradition is still ignored by some academic historians, who unquestioningly view the printed document as an invariably superior source.

Maclean himself passed down the importance of telling Scotland's and Gaeldom's authentic story. Not least to his son Coinneach who, in his late 50s, embarked on a doctoral thesis at Glasgow University which he hopes will be published in book form soon.

It exposes how Scotland's much vaunted tourism industry, which generates more than £4 billion of foreign exchange annually, either obscures the true story of Gaelic Scotland or airbrushes it out of its narrative altogether. This despite the landscape of the Highlands and Islands - the Gaidhealtachd - being the very image so often promoted by the industry.

It is as though the Gaels have been all but removed from the land they had cherished for an epoch. It was no wilderness. Every hillock, burn and lochan dignified by a Gaelic name at one time; the wildlife and environment central; all remembered in poetry and song.

As Highland historian Professor Jim Hunter put it: "For close on 1,500 years now, ever since the reciters of the Ulster sagas - drawing, perhaps, in Ireland on their knowledge of the Dalriada settlements - caused Deirdre to lament so eloquently her departure from her Scottish glen of steep-ridged peaks and pools and dappled deer and rowans and hawks and round-faced otters, our literature has consisted very largely of our efforts to explore the meaning of our place.''

But the Gaels' imprint has been remorselessly eroded. Maclean even sees the process being unintentionally aided by some of those who indubitably love this land today. The mountaineering fraternity for example, who bundle peaks such as the Five Sisters of Kintail or the Three Sisters of Glencoe together for anglicised convenience.

Maclean writes in his thesis: "Scotland represents one of the oldest sites of mass tourism, remains a significant part of the Scottish economy and there is a substantial corpus of literature on the nature of the Highlands of Scotland. But, paradoxically, the Gael (the Gaelic Scot) is reduced to a silenced subaltern 'other' under an unmediated 'tourist gaze'."

A Gaelic speaker himself, Maclean trained as an archaeologist. But his subsequent career choices ranged from deer farming, community business development and housing investment. They gave him a deep understanding of the economic and cultural challenges facing many communities north of the Highland line. His subsequent time as deputy chief executive of the NTS also afforded him an appreciation of the complexities involved in the stewardship of natural and heritage assets.

As part of his research Maclean went on a series of bus trips along Scotland's favoured tourist routes: Perth to Inverness with the likes of Killiecrankie on the way; Loch Ness to Fort William and Ben Nevis; Glencoe to Rannoch Moor and Loch Lomond.

He logged the historical and linguistic nonsense that often punctuated the commentary for visitors. They were told that Loch Ba on Rannoch Moor got its name from "the noise sheep make" when ironically it means loch of the cattle. Meanwhile Loch Lochy in the Great Glen is so called because the ancient Gaels couldn't think of another word (Loch Lochaidh means loch of the dark water).

The air quality in the Highlands apparently "leads to whiter sheep" and "'most of Inverness was destroyed by the last Jacobite rising', which it wasn't".

The hydroelectric generating hall at Inveruglas on Loch Lomondside was explained thus: "At this point the road used to flood with water from the hill. But this problem was cured by channelling it down in pipes and then they decided that they could generate electricity from the power of the water flow" - an interesting perspective on the development of hydro power.

Strontian had "at least four possible meanings", when it has one - the small fairy hill.

"Rob Roy was so physically challenged that he looked like a gorilla and his knuckles practically scraped the ground", and rather wonderfully "there was a bit of controversy when Ossian published his poems a couple of centuries ago". (Ossian was a legendary Celtic warrior and bard. James Macpherson, a native Gael from Badenoch, had gained fame then notoriety in the 1760s for the literary sensation of apparently finding and translating the ancient works of Ossian. But in fact most of it was his own creation.)

Maclean's own favourite was " the relatively harmless gem that heather thatch was used instead of slate because the house walls were too weak to withstand the weight. In reality the poor people had to use whatever material was at hand.

"Again there was the totally invented citing of the loss of the Ninth Roman Legion at Lix Toll, which was jazzed-up even more by claiming that the unfortunate Roman soldiers were eaten by supposedly cannibalistic Picts."

Also, Lix was supposed to represent the Roman numbers for 59. Why? Because it was 59 miles from Glasgow, of course. "In fact it derives from the Gaelic word for a flagstone or hard slope."

Maclean's decision to write the thesis had followed another career change. He had embarked on a course, validated by Edinburgh University, designed to produce advanced "blue badge" tourist guides. But he was shocked at some of the course content, or rather the lack of it.

"I was surprised and increasingly irritated by the almost total blanking of a Scottish Gaelic presence from both history and landscape. However, what concerned me more was that when reference was made to Gaelic culture it was treated as though it belonged to the Iron Age. The message was clear: it was a primitive language which was quite impenetrable and only capable of being mastered by gifted linguists. This in a Scotland which attracts people from around the globe, from across Africa and Asia, who manage to understand what they are hearing in English."

"It was one thing for the university to allow such nonsense to be peddled but what mattered more was that the students, who had paid good hard cash for the privilege, were being denied any knowledge that might have enabled them to effectively guide their clients through the Highlands."

He even heard one tutor reveal that when asked to speak a few words of Gaelic, any old gibberish would do.

The only reference to Gaelic in the literature of the course was in a poem in Scots by William Dunbar called The Flything of Dunbar and Kennedy II, which hardly promoted the language:

Mismaid monstour, ilk mone owt of they mynd,/

Renunce, ribald, thy rymyng, thow bot royis,/

Thy trechour tung hes tane ane heland strynd;/

And lawland ers wald mak a bettir noyis.

Maclean himself stepped forward and offered to give a couple of lectures by way of a general introduction to Gaeldom, and things have improved a bit since: "Happily the new programme of guide training which the Scottish Tourist Guide Association initiated now has a small component on Gaelic history and culture."

Maclean has an important message for the tourist industry. "All important tourist destinations across the world give high priority to delivering an authentic experience," he says. "Scotland is a mature destination and desperately needs to market itself on the strength of an authentic offering. At this time of raised awareness of our national identity, surely Scotland should tell its real story. For a start it would help if VisitScotland might consider paying a little more than lip service to Gaelic, given its absolutely central role in that story."

He says the Gaelic plan produced by the agency as a public body in response to the demands of the Gaelic Language (Scotland) Act 2005 deals entirely with "transactional matters" such as putting up signs and gives no strategic thought to how Gaelic might be used in offering visitors an authentic experience.

He suggests VisitScotland should support guide training initiatives. "Support for quality training should be accompanied by an accreditation scheme which might prevent any Tom, Dick and Harry setting themselves up to take money from unsuspecting tourists by spouting arrant nonsense about Gaelic Scotland."

But they are hardly alone on that front. Hugh Trevor-Roper, Lord Dacre, regius professor of modern history at Oxford (who famously and wrongly authenticated Hitler's diaries), gleefully claimed much of Scottish history and Gaelic culture was based on self-serving myths. Many of his arguments have been effectively challenged, not least by William Ferguson, the distinguished Edinburgh University historian, who wrote on the identity of the Scottish nation. He opined in the Scottish Historical Review in 2007:

"Nowhere is the absurdity of Trevor-Roper's 'Scotch history' more apparent than in his essay on Highland tradition in the well-known volume entitled The Invention of Tradition. Nearly everything he has to say in that prolonged sneer is either mistaken or wide of the mark. How people have been taken in by that feeble stuff has puzzled me for years."

But Coinneach Maclean says: "The problem is that too many, possibly in deference to his Oxford chair, have swallowed his ideas hook, line and sinker. It has become commonplace, for example, that his claims of an Englishman inventing the kilt are repeated as established historical fact by the likes of Jeremy Paxman. A millennium and a half of Gaelic tradition, apparently, is as naught in the face of an Oxford authority."

Maclean for one is doing his bit to set our record straight.