THOSE Carlsberg ads where good looking young professionals idle their way through the perfect this and that . . . holiday, flat, office . . . omit one obvious category. They have yet to spend thousands recreating the perfect pub. Well they can stop now. The perfect pub is found, but may now be lost forever.

Located down an unpromisingly dingy alley parallel to Dublin's Dame Street lies The Stag's Head, a landmark for Dublin's drinkers which may not survive the year in its preciously virginal state, untouched by the whims and mores of modern landlordry, the digital bells and spray-on-dusty Oirish whistles that have ruined the boozing life of the capital. On Wednesday it will be sold.

In 1993, when I arrived as an 18 -year-old student from Scotland, Dublin seemed to me to be a rainy version of heaven. In glorious contrast to the rash of theme pubs, chrome 'lifestyle' bars and increasingly desperate drinks promotions and gimmicks that still plague the streets of every British city, Dublin seemed to be full of precious ordinary pubs, places you could simply have a pint unmolested by the worst excesses of capitalistic hyperbole.

Something was happening, though, even in 1993. The shoots of an economic miracle were beginning to show and the tourism sector was booming. For a while the British stag party, now so reviled, was slavishly catered for. Stag parties even had their own little theme park, Temple Bar. A citywide conspiracy of recommending Temple Bar to any British accent that asked the best place to go kept the rest of Dublin blessedly stag-free.

Those stag party revellers remembered the times they'd had in Dublin, and swarmed en masse to the Irish themed bars that suddenly became flavour of the month in Britain. The hipness of anything Irish was useful in all sorts of ways to Irish people at home and abroad, and it seemed to be pretty self contained. But then something odd began to happen. As money began to circulate around Dublin in unprecedented volume, as property development became the quickest way to new riches, as pubs were overhauled, some of them began exhibiting some eerily familiar traits.

It began in hotel bars, those ambience vacuums that would try any old trick to entice their guests not to stray beyond the front door. The odd old bicycle appeared here, a copper kettle there, a violin nailed to the wall at a rakish angle: pubs in Dublin were being reinvented as Irish theme bars. No matter that they were Irish, they had to be recast in the palatable 'Irish' mould that would safely attract foreign punters.

That is a trend that, in tandem with the creation of modern minimalist bars, has now, 11 years later, seriously endangered those traditional pubs so emulated the world over.

A handful of bars in Temple Bar, including the Temple Bar itself, were modernised to cope with demand, quite understandably from the proprietor's point of view, but lamentably from the drinker's. The upstairs of Kehoe's was turned from a granny's living room style curio into just another lounge bar; O'Neill's now has so many TVs that it feels like a showroom.

The Stag's Head is in a different class from any of these, though. It is an archetype, so ruthless in its policing of its identity, so inflexible in its maintenance of its faded, slightly shabby grandeur, that it now stands as the template for a forgotten product, the recipe for a forgotten dish. You can watch TV in Mulligan's; you can use your mobile in The Long Hall; you can drink on a Sunday in the Gravedigger's. In the Stag's you can do none of these.

It is a pub at its best on a weekday afternoon, almost or completely empty with the grey light filtering through stained glass windows, the silent absence of music a tonic, the torn red leather of the couches in the snug an old-world comfort. The TV is only brought out to sit on beer crates for certain special occasions . . . Ireland rugby and football matches, Cheltenham . . . and is quickly whisked away again. No cigarette machine or one armed bandit clogs the hallways, no piped music assaults the ears.

I remember my first visit to this mythical place, supposedly the home from home for Trinity students who ventured off campus.

It seemed to be just another pub, full of braying self-absorbed posers who all knew one another and the bar staff. Eventually I became one of those posers, taking parental phone calls in the snug in those pre-mobile days, but even when I became too infrequent a visitor to recognise many punters or any bar staff the magic of a beautiful pub run as a vocation and not a job still held. It became a place remembered from so many angles at so many ages in so many states that it took on a calming presence of its own, reflecting memories back at me, nudging thoughts in this or that direction the way a childhood home does.

I have these, my own very personal reasons to lament any change to the Stag's, but should the new owner manage to get around the building's internal and external protected structure status to make changes, Dublin should lament too. This is one of the few examples left in the city centre of something that is important not because it has been exported around the world, not because it has the potential to make Dublin fatter and richer on tourist dollars and not because anything old deserves automatic protection. It is important because it is great, and, in our multimedia-festooned, noisy, constantlyrefitted pub ways, we have forgotten why.

After Wednesday we might forget forever.