1 Landmannalaugar, Iceland
The milky waters of the Blue Lagoon are an iconic image of Iceland, but for something less crowded and more natural, make for Landmannalaugar (landmannalaugar.info) in the centre of the island. It's inaccessible in winter, but by summer the road is clear and hikers arrive to soothe their muscles with a quick dip in the geothermal waters that feed into local brooks. Hire cars are forbidden to drive here, but there are regular buses from Reykjavik from mid-June to mid-September.
Stay: Landmannalaugar Hut sleeps 110 (bring your own sleeping bag) and costs around 2,200 krona (£13.50) per night or there is a campsite nearby (00 354 854 1192, July to September only)
2 Hveravellir, Iceland
Another slice of unadulterated nature in Iceland. Hveravellir (00 354 452 4200; hveravellir.is), means "hot spring plains" and is a nature reserve bracketed by two glaciers. It's popular with hikers and riders. There's a hot pool near one of the huts but the geothermal water also feeds into nearby streams for more temperate bathing.
Stay: Hveravellir Lodge (00 354 894 1293; hveravellir.is), dormitory beds from 3,500 krona (£21.60), double rooms from 10,000 krona per person (£61.70)
3 Matlock Bath, Derbyshire
More pleasingly warm than piping hot, the 18th-century indoor swimming pool at the New Bath Hotel (01629 583454; brook-hotels.co.uk) in Matlock Bath is filled by thermal waters. There's also an outdoor swimming pool fed by the spring, which is open from May to October. A day pass for both pools costs £5 for adults and £2.50 for children.
Stay: Hurdlow Grange (07866 778847; hurdlow.co.uk) has three-night breaks in a cottage sleeping six from £456
4 Bath
Once a holiday camp for Roman soldiers resting after the rigours of patrolling Hadrian's Wall, Bath (0844 888 0844; thermaebathspa.com) regained its crown as Britain's number one hot spring destination in 2006, with the opening of a new £45m public spa. Fed by springs below the city which pump out a million litres of water a day at 45C, the spa was designed by Nicholas Grimshaw and features a steaming, open-air rooftop pool with mesmerising views across the honey-coloured Georgian city. A two-hour session costs £22.
Stay: Rural Retreats (01386 701177; ruralretreats.co.uk) has a two-bedroom apartment in the Royal Crescent from £363 for a three-night stay
5 Bains De Dorres, France
France takes its thermal baths very seriously, surrounding them with white-coated doctors and state-sanctioned holidays. For something more natural, try the Bains de Dorres (00 33 4 6804 6687; bains-de-dorres.com) in the Pyrenees close to the Spanish border. These baths date back to Roman times and offer a chance to soak at 37-40C with stunning views of the valleys below. They are very popular with skiers and walkers, and are open daily from 8.30am to 8pm (except for a break from the end of November to the beginning of December). Tickets €4.
Stay: Just across the Spanish border are the Pyrenean Mountain Apartments, where a week with Inntravel (01653 617906; inntravel.co.uk) costs from £398 per person
6 Chaudfontaine, Belgium
Its name is the big clue to this village's raison d'etre. In the middle of the Vesdre valley, not far from Liège, Chaudfontaine (00 32 4367 8067; chateaudesthermes.be) has the hottest thermal water in Belgium. It comes out of the ground at 34C. Posh but accessible, this spa within a chateau is open for overnight stays and day visits - travel by train from Brussels to Liège. With hydrojets and Turkish baths and French cuisine, this is a very Gallic take on the spa experience. A one-day ticket costs €30.
Stay: Le White Room (00 32 2538 5995; lewhiteroom.be), has doubles from €70 including breakfast
7 Spreeworld, Germany
Compared with the formalised, decidedly posh Belle Epoque spa experience that is Baden-Baden, Spreewald (00 49 35603 18850; spreewald-therme.de) prefers to take a low-key approach, partnering airy modern architecture and a serene forest environment with some highly mineralised water that comes out of the ground at 51C. An easy day-trip from Berlin - Spreewald is an hour away by train - this is a thermal spa that would work well as part of a cycling or walking holiday. A day ticket is €23, two hours from €12.
Stay: One of Germany's nicest campsites (00 49 3542 3533; spreewald-camping.de) shares this forest. Pitches for tents and campervans start at €1.50
8 Wiesbaden, Germany
Opened as an "orthopaedic healing institute" in 1836 to take advantage of the 66C water, the Kaiser-Friedrich-Therme indoor bath (wiesbaden.de), created in art nouveau style in 1913, is a much-cherished historic monument, lavishly decorated with Jugendstil ceramics and frescos. Among its glorious conglomeration of European bathing traditions, you'll find an Irish-Roman bath and a Russian steam bath as well as tepidariums and hot rooms. Entry costs €3.50 an hour in summer, €5 in winter and Wiesbaden is within easy reach of Stuttgart.
Stay: Hotel Alexander (00 49 61199 2850; hotel-alexander.com), B&B doubles from €69
9 Therme Vals, Switzerland
9 The most minimal, achingly trendy natural hot springs in Europe, possibly in the world, are a 200km journey by train and bus from Zurich. In 1986, the villagers of Vals hired leading architect Peter Zumthor. Ten years and 60,000 slabs of quartz later, he had surrounded their hot springs with a cutting-edge building (00 41 81 926 8080; www.therme-vals.ch). The mineral-rich water emerges at 29.4C, though the hydrotherapy pools range in temperature from 32C to 42C degrees. For added impact, composer Fritz Hauser has created some special music for the relaxation room. Stay at the adjacent hotel, which is gradually being remodelled by Zumthor, and you can swim until midnight. Tickets: adults 40CHF (£24), children 26CHF (£16).
Stay: Doubles from 214CHF (£128) including breakfast
10 Ischia, Italy
Most hotels on this Italian island seem to come with their own thermal baths, but as a stand-alone spa Negombo (00 39 081 986152; negombo.it) tries harder. In an idyllic location overlooking a bay, Negombo is a blend of sculpture park, beach and watery playground, with some rare plants added for good measure. For the best experience, buy a day ticket, arrive early and spend the day exploring the site. The treatments range from the indulgent (an open-air massage amid scented plants) to the muscular-skeletally rigorous. Tickets: €29. Negombo reopens on 23 April.
Stay: Thomas Cook (0844 412 5970; thomascook.com) has seven nights in Ischia from £688 at the four-star Clarion Hermitage hotel in Ischia Porto, including half-board accommodation, flights to Naples and transfers
11 Pantelleria, Italy
This tiny island near the coast of Tunisia is dotted with steaming fumeroles but volcanic activity is put to most practical use in the harbour at Gadir. Throughout the year villagers and holidaymakers - including Giorgio Armani who has had a holiday home in the village for decades - wander down to the harbour to immerse themselves in the hot water. Rough concrete encases the thermal water at the side of the harbour. No formalities, no charge - and devotees swear that it helps rheumatism and arthritis.
Stay: Holiday Options (0844 477 0452; holidayoptions.co.uk) has a seven-night holiday in early May at the four-star Hotel Club Levante for £1,639, including flights from Stansted, B&B and some dinners
12 Aquadome, Austria
Discovered in the 16th century but re-engineered for the 21st, the geothermal spring at Langenfeld (aqua-dome.at) has become an Alpine playground with a generous complex of indoor and outdoor pools. There are also three thermal pools hovering above the landscape in giant bowls with temperatures ranging from 24C to 34C, plus hydrojets. A three-hour pass costs €16.
Discovered in the 16th century but re-engineered for the 21st, the geothermal spring at Langenfeld (aqua-dome.at) has become an Alpine playground with a generous complex of indoor and outdoor pools. There are also three thermal pools hovering above the landscape in giant bowls with temperatures ranging from 24C to 34C, plus hydrojets. A three-hour pass costs €16.
Stay: Naturhotel Waldklause (00 43 5253 5455; waldklause.at) has half-board doubles from €115
13 Bad Blumau, Austria
Bathers at Bad Blumau (00 43 3383 5100; blumau.com) can swim between indoor and outdoor pools fed by two natural hot springs, the experience enhanced by underwater music and the undulating, uplifting rainbow-coloured architecture of Friedrich Hundertwasser. The Vulkania curative spring, with 110C water straight from a spring almost 1km deep erupts with the help of a fake volcano, adds an element of high camp. There's a welcoming attitude to younger visitors to match the Teletubby architecture (children get their own pools), while serious middle European treatments, including physiotherapy and sports massages, are also on offer. You could stay in a chalet nearby but you might want to stay under the turfed roof of the Bad Blumau hotel itself. Day rates: adults from €37, children (6-12 years) €19.
Stay: Double rooms at Bad Blumau with half board start at €128 per person. Ryanair (ryanair.com) flies from Stansted to Graz
14 Bad Gastein, Austria
In the Austrian Alps, Felsen Therme (felsentherme.com) does big business with the post-ski crowd (the complex is open until 10pm every day and 11pm on Thursdays) but also offers succour to the ski-phobic. A complex of 18 radon-rich springs, its indoor pool is embedded into the rock beside salt caves and saunas, while the outdoor pool has sunning platforms and views across to the Hohe Tauern mountains from the steaming water. A three-hour ticket costs €19.
Stay: Crystal Ski (0871 231 2256; crystalski.co.uk) has a week's stay in the three-star Hotel Alpenblick in Bad Gastein from £459, including flights from Gatwick, transfers and half board.
15 Budapest, Hungary
Budapest has ruthlessly exploited its situation on a geographical fault line: 120 hot springs feed numerous pools and baths across the city. The Lukacs Baths (00 36 1326 1695; spasbudapest.com) is a sprawling complex of indoor and outdoor pools and mud lounges which have a pleasing tinge of eastern European utilitarianism about them, and are deservedly popular with chess-playing octogenarians. Since they are part of a hospital, wheelchair access is good and specialist physiotherapy treatments are also available. Open all year round.
Stay: Budapest Apartments (00 36 1877 6227; budapestapartments.co.uk) from €40 for a double studio
16 Heviz, Hungary
Hungary's largest thermal lake gives its name to the spa town of Heviz (heviz.hu). Thanks to a hot spring almost 40m below ground, the temperature of the lake never dips below 23C, even in winter, allowing swimmers to float alongside the pink and white lotus all year round. It is traditional to hire rubber rings to soak for a few hours, then repair to one of the fin de siècle pavilions to rest on loungers. The spa's nine indoor pools (00 36 8350 1700; spaheviz.hu) range in temperature from 32-37C. Nearby hotels add to the spa experience with mud baths, saunas and treatments.
Stay: Danubius Health Spa Resort Heviz (00 36 8388 9400;danubiushotels.com) has doubles from €114
17 Piestany, Slovakia
Mud is big at Piestany (spapiestany.sk), Slovakia's best-established hot springs, 86km from Bratislava. The main pools are housed on Spa Island, a wooded park that aims to impart sanatorium-style serenity. Although most hotels require you to stay in their hotels before you can use the thermal pools, the water park at the Hotel Balnea Esplanade allows you entry for €26 a day, the price including the use of interconnected indoor and outdoor swimming pools heated to 34C, plus massage jets and whirlpool baths, saunas and steam baths.
Stay: The Hotel Pavla (00421 33 774 34 22; hotelpavla.com) has doubles from €115 including breakfast
18 Rogaska Spa, Slovenia
This is a Belle Epoque palace wrapped in a quintessentially 19th-century Eastern European spa town. Surrounding the hotel (terme-rogaska.si) is a series of pools, with temperatures from 27C to 36C, massage baths and therapeutic waterfalls. The magnesium and calcium-rich water also contains lithium and bromide, said to aid digestion. Adult entry costs €9 a day.
This is a Belle Epoque palace wrapped in a quintessentially 19th-century Eastern European spa town. Surrounding the hotel (terme-rogaska.si) is a series of pools, with temperatures from 27C to 36C, massage baths and therapeutic waterfalls. The magnesium and calcium-rich water also contains lithium and bromide, said to aid digestion. Adult entry costs €9 a day.
Stay: Thermalia Spas (020 8950 2970; thermaliaspas.co.uk) has four nights at the Grand Hotel Sava for £499 including flights to Ljubljana, transfers, half-board accommodation and two Thai massages
19 Santorini, Greece
Palia Kameni is a refreshingly uncommercial hot springs experience on this most polished of Greek islands. It has copper-coloured rocks and deep green water and habitués to the plethora of walk-in springs slather themselves with sulphurous mud. To do the same, book a trip to Ammoudi or hire a boat and head along the coast until you reach the bay of Palia Kameni where water from the springs pours into the sea.
Stay: Manos (0844 879 8200; thomascook.com/brands/manos) has seven nights at the Aegean Plaza Hotel in Kamari from £387, including flights, transfers and B&B accommodation
20 Lemnos, Greece
This island in the Aegean is popular with windsurfers and there are a series of DIY mud baths and hot springs to ease their muscles after a long day. Daily boat trips are also available to Samothraki, an island that boasts some of the best hot springs in Greece as well as a series of waterfalls and rock pools in which to cool off afterwards.
This island in the Aegean is popular with windsurfers and there are a series of DIY mud baths and hot springs to ease their muscles after a long day. Daily boat trips are also available to Samothraki, an island that boasts some of the best hot springs in Greece as well as a series of waterfalls and rock pools in which to cool off afterwards.
Stay: Sunvil Holidays (020 8758 4758; sunvil.co.uk) offers seven nights' self-catering from £585 at the Sotiris Apartments near Myrina, including flights and transfers