October; the english midlands; the first named storm of the season: for the aficionado of low light levels, it doesnt get better than this. looking out of the window of the train from stockport to buxton, its as if someone has dimmed the screen brightness to its lowest setting. through the rain-flecked glass, the cuttings are a deep, dank green, verging on black; when a more distant perspective pulls into view between dripping trees, you can see the tops of the peak district hills blurring into low grey cloud.

If its not the most welcoming weather for the first-time visitor to buxton, its at least appropriate: this derbyshire spa town is built on rain. the warm spring that has drawn visitors for centuries, and filled 230m bottles of mineral water last year alone, is fed by the precipitation that falls on the nearby limestone hills.

As it percolates through the rock, it flows broadly northward, accumulating minerals and subterranean heat as it goes. at buxton, however, the geology changes and, its progress impeded by impermeable gritstone, the water rises to the surface again, some 5,000 years after it left the cloud.

Roman settlers, medieval pilgrims and 18th-century industrialists have all drunk deeply. now buxton is hoping that a new generation of visitors will make it their destination.

The crescent, the towns elegant georgian hotel-cum-landmark, reopens this month following a redevelopment that has cost 70m and taken almost three decades, thanks to legal wrangles, funding difficulties and geological conundrums. just as in bygone centuries, guests can once more take the waters in a pool near the spring; unlike their predecessors, they can lounge in front of flatscreen tvs in their rooms while scoffing truffle and parmesan-crusted chips afterwards.

Buxton crescent, with the hills of the peak district beyond

The story of the crescent is one of shifts both in popular taste and in economic luck. it was the brainchild of william cavendish, the 5th duke of devonshire, one of the wealthiest landowners in 18th-century england. seeing the success of the spa at bath, to which the beau monde had been flocking in the preceding decades, he decided to turn the water welling on his land in buxton to similarly lucrative account.

Cavendish hired the architect john carr, a prolific builder of grand houses in and around neighbouring yorkshire, and between 1780 and 1789 he delivered a masterpiece: the four-storey, semicircular stone terrace, with its arcaded walk and 30 low-relief columns, would be an impressive addition to a capital city, let alone a market town.

Like a neoclassical horseshoe magnet, the crescent attracted well-heeled visitors to take the waters under doctors orders and, under a different set of imperatives, to dance in the assembly room, play cards and exchange gossip. many, such as the pottery entrepreneur josiah wedgwood, came from families that were prospering as the industrial revolution transformed neighbouring cities. others came from older money, including cavendishs wife georgiana, a high-society celebrity whose fame eclipsed her husbands. we shall live the wholesomest of lives here, she wrote.

The town continued to prosper in the victorian era, especially after the railway arrived in the 1860s. by 1905, more than 300 hotels and lodging houses were serving some 4,000 visitors a week, who could also avail themselves of handsome public gardens, a grand glass pavilion and an opera house. it was during this period too that the buxton mineral water company started bottling the spring water and selling it to health-conscious customers throughout england.

An image of the crescent from the illustrated london news in 1854, when buxton continued to prosper. by 1905, the towns hotels and lodging houses were serving some 4,000 visitors a week

The 20th century was less kind. coastal resorts ate into buxtons market share, while the creation of the national health service after the second world war proved fatal: why pay to go to a spa for the sake of your health? the crescent languished. in the 1970s, one end became council offices, with the assembly room being repurposed as a municipal library. at the other end, st anns hotel named after the saint to whom pious medieval visitors dedicated the spring lingered on until 1989.

By the 1990s, the roof was protected with plastic sheeting and windows were boarded up. it was clear something needed to be done to save the grade i listed building, though doing so has proved anything but straightforward local authorities in 21st-century england have neither the wealth nor the freedom enjoyed by 18th-century aristocrats.

Map of buxton, derbyshire

Grants from national heritage organisations enabled the borough council to buy out the crescents private owners and then, by the mid-1990s, to carry out the structural work needed to keep the building standing. but full-scale restoration was beyond the reach of the public purse and too risky for private investors to take on alone.

Eventually, both sources were tapped, with public money, to the tune ultimately of about 40m, coming from the uks national lottery heritage fund and from local councils, and an alliance of property and hotel developers buxton crescent ltd providing more than 30m.

Adding yet more complexity were fears that any building work might interfere with the spring, which lies adjacent to the crescent. the projects big investors were not the only ones to be concerned: so too was nestl, the swiss multinational that had acquired the buxton mineral water company in 1992 and with it a licence, granted by the council, to bottle and sell the water. it insisted that the building works must not be allowed to contaminate the water or diminish its flow.

The dining room: there is real character, which has survived the years of rebuilding

Hydrogeologists became involved. so did lawyers. eventually, an agreement was reached that required any work that might conceivably affect the spring to be detailed in a so-called method statement; this then had to be signed off by three independent experts, commissioned respectively by nestl, the council and the developers.

Today the dark fissure from which the water pours forth is sealed in a sterile metal pod. access is limited, quality constantly monitored and everyone gets their cut.one pipe carries the water to the nestl plant on waterswallows lane (yes, really) a couple of miles outside town. another, much shorter, connection runs just across the road to supply st anns well, where, beneath a little bronze statue of the saint and her daughter mary, a constantly flowing pipe fulfils the councils legal obligation to provide public access to the water.

And since last weekend, guests of the buxton crescent hotel also get a share, as the spring supplies the basement thermal pool. this is heated beyond the 27.5c that the water emerges from the ground at: while it is a thrill on a chilly day to feel the tepid warmth of the water gushing from the st anns well pipe, you wouldnt want to soak in it for long. at the higher temperature, though, its a pleasure to relax into it: to admire the blue-and-green stained-glass canopy overhead, to reflect on the novelty of following in the damp footsteps of health-conscious georgians while soaking in several supermarkets-worth of buxton mineral water.

The rooftop pool

Since the hotel is operated by ensana, a european chain specialising in spas, there are multiple treatment options. i sampled the signature wave balance basically a massage on a waterbed; unwound to the point of stupefaction, i rippled up and down like a strand of seaweed on the tide.

The outstanding facility, though, was the rooftop pool, which is heated to a pleasant bath-time temperature and from where you can survey the crescent curving away as scuds of steam whip off the surface. or you can haul yourself out and watch the passers-by on the grey streets below though i think, judging from a shout that i couldnt quite catch, that i cut a deranged rather than impressive figure in the teeming rain. but it was sheer pleasure to slip back into the pool and, holding dead still, to watch the raindrops plopping and rebounding into the water all around.

The newly refurbished bar

The hotel itself is no less luxurious: the beds are intensely comfortable, the showers immediately warm and drenching, the food rich and delicious, the service attentive. yet there is real character, too, which has survived decades of neglect and years of arduous rebuilding.

The restored assembly room, with its original chandeliers, gilt-topped corinthian columns and ornate ceiling, is a neoclassical stunner: surely the effect carr intended. but his vision emerges in more subtle ways too. modern access requirements and expectations of en suite facilities mean the rooms are not all where carr positioned them; yet the corridor still follows the curve of the building, making it easy, as it must always have been, to navigate and to lose sight of ones companions. in a nice touch, many of the georgian doors and fanlights have been painstakingly returned to their original positions, though not opening on to anything. only a ghost could get through them now.

Bathroom with view of the town

The most obvious encounter with the past, though, comes when you step back and admire the building itself. after long years of dereliction, the dazzling attraction that cavendish envisaged has finally re-emerged. among the hotels staff are many twentysomethings who have grown up with the crescent behind hoardings. not that its fully open even now: coronavirus has inflicted yet another delay, with access temporarily restricted to guests and staff only. would-be visitors are left to peer in through the ground-floor windows, as they disconcertingly did while i had lunch in the bar. this must be what its like to be a celebrity, i thought though here the building was the a-lister.

On saturday night i stepped across the road to sample the water from st anns well. i was not the only one: already there was a tall man beneath a broad umbrella, watching the water level slowly rise in a big plastic jerry can. obligingly, he let me fill my little bottle and we got talking. he had, he said, driven 60 miles, from lancashire, to get his weeks supply. wouldnt it be easier, i asked, to get it from the tap? he looked at me as if i were missing the point. once youve tried this, he said, you dont want to go back to tap water.

As i sipped the crystal-clear, weirdly tepid contents of my bottle, i could see what he meant. there is something magical about that spring.

Neville hawcock was a guest of the buxton crescent hotel; doubles cost from 125. for information on the area, and the latest on coronavirus-related restrictions see

Follow on twitter to find out about our latest stories first