Out of the Tuscan sun

I've been to hell and back – and it's not what you might expect. Contrary to popular belief, the road isn't paved with good intentions, but with concrete.

In the dimly lit afterlife, towering stalagmites and dagger-like stalactites punctuate corridors that wind through dimpled rock, like the pathways of a giant, labyrinthine brain. There are even handrails to prevent you from falling into the abyss.

Fortunately for me, this intriguing netherworld is actually the largest thermal cave in Europe, nestled deep withinthe Grotta Giusti resort in Tuscany. Quarry workers accidentally discovered the grotto, home to a 130 million-year-old mineral-rich spring, in 1849 near the villa of Italian poet Giuseppe Giusti. Shortly afterward, the entrepreneurial wordsmith converted his estate into a spa and hotel.

When the 19 th-century composer Giuseppe Verdi gave the grotto a big thumbs up, dubbing it "the eighth wonder of the world," its reputation was made.

Today, the enterprise encompasses a 64-room hotel, which debuted a €15-million ($22.7-million) refurbishment this spring, revealing refreshed guestrooms and a lighter, airier restaurant and piano bar, without sacrificing the villa's original frescoes and selection of period antiques. Two outdoor thermal pools feature hydro-massage jets, where guests bob like poached eggs, and an expansive spa offers everything from massage to mud therapy, anti-aging and anti-cellulite treatments, and a recently launched "Equilibrium" program focusing on nutrition, relaxation techniques, thermal therapy and exercise. The surrounding 45-hectare park provides plenty of ways to escape the creeping tendrils of inertia, with a hiking trail, tennis courts, rock climbing and paragliding, while a nearby golf course treats guests to a discount.

It's the grotto, though, that steals the show. Vapours from the thermal spring transform the cavern into a natural sauna where temperatures vary from around 28 to 36 degrees. A 50-minute tour is meant to alleviate a laundry list of ailments, including respiratory, circulatory, osteo-muscular, nervous and skin conditions.

According to the hotel's marketing director, Barbara Guidi, "the heat helps muscles totally relax and absorb these minerals into the bones. It stimulates the production of endorphins, which is why you feel so relaxed. It's like a drug."

In fact, it's so much like a drug that the Italian government subsidizes citizens' visits here.

Visitors can also enjoy full immersion therapy – a baptism, if you like – in the Lago del Limbo, the crystal clear, 34-degree lake that stretches out beneath the cavern's cathedral-like arches. Grotta Giusti offers the rare opportunity to scuba dive in a thermal cave system, but as I've always been keen on breathing oxygen that doesn't come from a can, I opt instead for "flotation therapy" in the lake with cave guide Luciano Tanini, who has been exploring these caves since 1980.

Cradling me in his arms, Luciano stretches and bends my limbs as he moves me gently through the balmy water. Swaying like seaweed, entrusting myself to the strong hands of a stranger, I'm as carefree as flotsam and jetsam on an infinite ocean.

You might even say that I'm as happy as a pig in mud … but just what is it about mud that's supposed to induce such euphoria? That's what I aim to find out when I travel 45 kilometres west to Bagni di Pisa, which places a special emphasis on fangotherapy. (It's nothing to do with vampires. That's spa-speak for detoxifying, anti-inflammatory treatments using hot clay steeped in thermal waters.)

Like Grotta Giusti, the 61-room Bagni di Pisa is part of the Italian Hospitality Collection, and it's also housed in a historic Tuscan property with a renowned thermal spa. The Bagni di Pisa villa, replete with historic frescoes, was owned by the Medicis before the Lorena family adopted it as their summer residence, six kilometres from the city of Pisa.

Through the centuries, Bagni di Pisa has hosted illustrious guests such as George IV of England, Lord Byron and Mary Shelley, for whom the hotel's glamorous Shelley Bar is named. (Maybe Mary dreamt up Frankenstein after one too many martinis?) It's easy to imagine such glitterati sitting down to dinner in the elegant Dei Lorena restaurant, although perhaps not so casually attired as some guests today, who don't hesitate to rock up in their spa robes and slippers, particularly at lunch.

Set amid flowering fruit trees and botanical gardens, Bagni di Pisa features an outdoor thermal pool and four indoor pools; the Hammam dei Granduchi, a romantic natural grotto with a two-person bath fed by a thermal waterfall, and the Salidarium, where I'm buried up to my neck in a bed of warm salt crystals, emerging some 20 minutes later feeling as delectable as a salted cod.

But the resort's pièce de résistance is the aforementioned fangotherapy, which is also subsidized by the Italian government. Before I meet the mud, a man in a white lab coat takes my blood pressure, which proves to be low – hardly surprising, given that I've already spent two days kicking back at Grotta Giusti.

After he explains that the mineral-infused mud will be applied to my back, shoulders and flanks, I'm ushered to the treatment area, where I meet Rossella. With her mass of black curls framing a kindly face, she just about puts me at ease, despite the fact that she's wearing a plastic apron and gloves. (It's possible I've seen too many episodes of Dexter.)

Stripping down to a pair of paper panties, I sit on bed enshrouded in gauze while Rossella slathers me in medicinal muck dispensed from an industrial-looking silver pipe. Then she swaddles me in a sheet of plastic and a thick orange blanket before easing me onto my back, where I lay like a helpless burrito.

" Cinque, cinque, cinque!" Rossella smiles, flashing five fingers at me repeatedly to indicate that I'll baste for fifteen minutes. Occasionally, she returns to check on my progress, mopping my brow with a tissue and bestowing a beatific smile, like Mother Teresa in a Saran Wrap habit.

When Rossella finally frees me from my cocoon, such is her delight that you would have thought she was unwrapping her first bicycle, rather than my sweating, shrivelled carcass. "Bueno!" she says, clapping her hands, clearly pleased with the lagoon of perspiration I've produced. Never have I been so roundly applauded for so little effort, but nevertheless, I feel myself blushing with pride … or possibly heatstroke.

Finally, Rossella leads me to a warm tub, leaving me to simmer like suet pudding. Closing my eyes, I take stock of my various body parts and realize that, for the first time in ages, the tangled knots of tension that usually plague my back are gone.

Perhaps we should all take a page from the piggies' playbook. I think I've found my paradise at last.

The writer was a guest of the Italian Hospitality Collection. It did not review or approve this article.

If you go

Grotta Giusti is about a 50-minute drive from the Pisa and Florence airports. Bagni di Pisa is 20 minutes from the Pisa airport and approximately an hour from the Florence airport.

Where to stay

Grotta Giusti, four-star resort in Monsummano Terme, from €135 ($200) a person, grottagiustispa.com.

Bagni di Pisa, five-star resort in San Giuliano Terme, from €144 ($215) a person, bagnidipisa.com.

The Italian Hospitality Collection also includes a third Tuscan resort, Fonteverde, which features along with Grotta Giusti and Bagni di Pisa on the new nine-night "Tuscan Route." All three properties offer thermal spas and the collection's signature Equilibrium program, developed by Dr. Nicola Angelo Fortunati. For details, visit italianhospitalitycollection.com.