This week Arnold Evans arrives in Bath, where the crescents and squares resonate with characters from Jane Austen. Some towns are best savoured in small sips; Bath, like its famous waters, should be taken in one long contemplative gulp. Approach the town via Widcombe Hill, and you can see the whole of it, spread out below you in all its Georgian splendour. An impeccable essay in soft honeyed sandstone, its tiers of crescents, squares, and colonnaded terraces curl up the valley sides a whirlpool of elegance and good taste.

Although it’s a town that has attracted more than its fair share of the braggardly and the bumptious, few can have been both as cocksure and as clueless as I was when I first gazed down on it at the age of 17. All ego, acne, attitude and O-levels, I was hitching from Wales (which I’d grown too big for) to the Edinburgh Festival (which I felt might just possibly be ready for me). But the moment I saw Bath, golden in the August sunlight, I realised I need travel no further. This was my kind of town: here I’d be able to show just how dead couth I was and pull posh birds. Enter Beau Evans (swaggering).

Most other towns have been chewed into shape by the dogs of war, or are a haphazard series of additions and deletions inflicted by each new generation as it clumsily refashions streets and buildings in its own image. Vast tracts of Bath, however, have remained unscathed for more than 200 years. It is still essentially “the new town” that was purpose-built in the 18th century: a holiday village for the well-to-do on their summer sojourn to take the waters.

By some stroke of luck, not just a few buildings, but the whole geometry and spirit of that original design have survived remarkably intact. Hitler did his damnedest, and successive town councils in the 1950s and 60s carried out “improvements” but now Unesco has designated the town “A World Heritage Site” and thus protected it from the bureaucrats’ bulldozers only Rome and Florence have been similarly honoured. Bath deserves the accolade. Here, you can step back in time as effortlessly as the town itself seems to have side-stepped the two centuries since it was built. It has a remarkable homogeneity: every street, skyline and vista melds into the same seamless whole. Every precisely-judged block of sandstone seems to sing the same song. It’s a jubilant song: a celebration that, maybe, all is for the best in the best of all possible worlds.

But this unmistakable sense of well-being that the town inspires can’t be attributed solely to the architects’ skills. Joie de vivre has bubbled in this place for as long as the spring of mysteriously hot water which has been tempting visitors here for nearly 3,000 years. The first, apparently, were a herd of leprous swine. They wallowed in the warm mud and were instantly restored to full health. Their swineherd, Bladud, also had leprosy so he naturally joined his newly cured bacon in the mud bath. Healed, he set about reclaiming his place in court and eventually became “eighth king of the Britons”. Out of gratitude, in 863 BC he built a temple to Minerva at the spring, established the tradition of bathing and sired Lear who went on to become a far more famous king than his dad (except in Bath, that is).

The legend, duly commemorated in Bath’s Pump Room, doesn’t say what became of the swine or whom they may have sired possibly those town councils of the Fifties and Sixties. Having paid homage to Bladud, visitors must sample the water. One small glass is more than enough bath water’s easier to swallow than Bath’s water. It arrives at a temperature of 46.5 C, rich in natural minerals and unpleasant enough to make you feel that it ought to be medicinal. It has been credited with all manner of curative powers which may or may not be true.

What is certain is that it has done the people of Bath a power of good. Excavations of the Roman shrine built on the site of Bladud’s temple unearthed over 13,000 Roman coins slung into the water by hopeful supplicants. And visitors to Bath, full of the joys of the spring, have been throwing their money around ever since. There are enough museums (of fashion, photography, the postal service, for instance), art galleries, restaurants, tea rooms and the snazziest of shops only too ready to relieve you of your loose change. But as you’d expect in Bath it’s all done in the best possible taste.

Visitors, even those with an allergic reaction to ancient history, must visit the excavated Roman Baths. Here they can dip their toes in the waters, and learn more than they could possibly want to know about the Romans’ obsessive preoccupation with their ablutions. They spent so long wallowing, it’s hard to see how they ever had any time left to divide Gaul into three parts or learn their Latin pluperfects.

The fastidious Romans must have left the baths as they’d wish to find them when they withdrew from the town in the early 5th century. The Brits who continued to use them weren’t nearly as pernickety. The baths became terribly squalid but visitors, nonetheless, continued to arrive in their droves. They were attracted both by the water’s alleged healing powers and by the excuse the baths offered for a spot of mixed skinny dipping the twin appeal of a Lourdes and a Club 18-30 holiday.

By the 18th century, the proprieties were restored. Ladies bathed clothed from neck to toe in voluminous canvas drawers and jackets which swelled with the water disguising any hint of the figure within. Not even the most libidinous male, presumably, could have been aroused by the spectacle of a flotilla of Ms Blobbys.

Of course, it wasn’t really the bathing that won Bath its unique place in the Georgians’ already-crowded social calendar. High society came to the place because it was the place to come to: a Matterhorn for social climbers, a Smithfield for single men of good fortune in want of a wife and a happy huntin’ ground for those fond mamas anxious to see their daughters safely betrothed in time for a spring wedding.

This is the universe Jane Austen mapped for us in such revealing detail. Indeed, she lived in Bath for a while and set most of Northanger Abbey and Persuasion in the town. Walking the streets that she walked, it’s easy to imagine brushing shoulders with Anne Elliot and Captain Wentworth.

Throughout its halcyon days, this exclusive little world had its undisputed king. Beau Nash inspired the building of the new town. His statue watches visitors in the Pump Room, as the man himself once kept his avuncular eye on his subjects as they danced, gambled, fussed with tea cups, or exchanged knowing glances in the candle light. Bath was a blue-bloods’ Butlins, and Nash, as official “Master of Ceremonies”, ruthlessly orchestrated their leisure time for them: it’s so much easier to have a good time when you have someone who tells you precisely how to have it.

Today, with no Nash to chivvy you, you have to discover the delights of 18th century Bath for yourself. It helps if you visit the museum at Number 1, Royal Crescent where a typical Georgian home has been faithfully recreated. You can study what was a la mode at the Museum of Costume, and then, in the Abbey, the Pump Room or under the chandeliers in the Assembly Rooms, imagine Bath in its heyday.

Better still, simply wander through the town. It’s a gargantuan film set in which you will soon cast yourself in the leading role as surely as I always do. I walk the languorous curve of the Royal Crescent with the air of a man who might own the place. I window-shop on Pulteney Bridge (Bath’s own Ponte Vecchio). I promenade ostentatiously on George Street, its conveniently-raised pavement a suitable stage for those who want not merely to see but to be seen. I may take tea in Sally Lunn’s just as Austen, Pope, and Dr Johnson would have done. “Hello, Beau Evans,” they chorus.

They are not the only ghosts the town is alive with them: throngs of the crinolined and the frock-coated who could never quite bring themselves to accept that their holiday was over. The gentlemen can’t drag themselves from the gaming tables where they wait eternally for that winning flush; the ladies flutter through the shops and streets in their ceaseless quest for the very best baubles, bangles, buttons and beaux. I usually hang around long enough to hear the voice that I thought I heard when I was 17. Drifting from across the centuries, it’s that of some demure daughter of the shires whispering to her mama. “That Beau Evans is dead couth. I wouldn’t mind if he tried to pull me.”

Had we but world enough and time! But I have to continue that journey I failed to complete nearly 30 years ago, and find out if Edinburgh is ready for me yet.