In search of... the best bath in Japan

Onsen (mineral hot springs) bathing is an integral part of the Japanese culture. Traditionally, these rural retreats were places to ease the aching muscles of rice farmers post-harvest. About 2,000 onsen remain scattered across Japan from the frozen north of Hokkaido to the tropical south of Kyushu.

Onsen (mineral hot springs) bathing is an integral part of the Japanese culture. Traditionally, these rural retreats were places to ease the aching muscles of rice farmers post-harvest. About 2,000 onsen remain scattered across Japan from the frozen north of Hokkaido to the tropical south of Kyushu.

Where's the best place for a soak then?

The Tohoku region of northern Honshu – Japan's main island – is home to some of the best onsen in Asia, places that hark back to the rural traditions of feudal Japan. The region used to be known as Michinoku, which means "the end of the road" and, even today, its six prefectures are relatively untouched. Hence, just a few hours from Tokyo by bullet train, you can find yourself in a completely different world.

But don't the remote rural locations make them hard to get to?

The best onsen are easily accessible from Tokyo. The latest extension to Japan's supremely efficient bullet train network, unveiled in December 2002, looks set to help open up the relatively unexplored far north of Japan. The new Japan Railways East Tohoku Shinkansen line extends from Tokyo to its northern terminus at Hachinohe, cutting the journey time from Tokyo Ueno station to three hours. To get around, simply buy a JR East Pass. The pass is valid for unlimited use of JR and bullet trains, the Narita Express from Tokyo's international airport, as well as discounts on JR-run buses. Passes must be purchased outside Japan and validated at the Travel Service Centre or a major train station before use. Prices for 2003: 5-day, 10-day and flexible 4-day passes cost ¥20,000 (£107), ¥32,000 (£171) and ¥20,000 (£107) respectively.

I could do with cooling off while waiting for my train. Any options?

Some bullet train stations have their own onsen in the station complex. Takahata JR station (00 81 238 57 3844), 40 minutes south of the Yamagata bullet train terminus on the JR Ou main line, is one of the best. This provincial station has full-scale bathhouse, the Mahoroba onsen, which opens 7am-9.30pm daily. A dip costs ¥200 (£1.10).

Right, I'm sold. Let me go and lather up.

Hang on. Before you strip off and dive in, a word of warning: the etiquette that accompanies getting naked with a bunch of strangers is just one of the danger areas in which unknowing visitors to Japan may find themselves – quite literally – in hot water. Get it wrong and you might as well relieve yourself in the koi carp pond – the normally polite Japanese will be seriously affronted. The key is to wash yourself outside the bath and keep the bath for soaking. Getting soap in the water is the most heinous of onsen faux pas.

It's a serious business then?

Absolutely. For onsen fans the ultimate goal is to attain a state of onsen nirvana known as yude-dako or "the boiled octopus", which stems from several hours of serious soaking.

Actually, I'm only on a short stopover in Tokyo. Is there anywhere for me to take a dip in the city?

Yes, several onsen survive tucked away down the side streets of Tokyo's neon-lit urban jungle. One of the best is the traditional Rokuryu (00 81 3 3821 3826) in Tokyo's Ueno district. Thissento (bathhouse) remains frozen in time and is deservedly popular with locals. The piping-hot amber waters contain mineral extracts reputedly good for skin ailments. It opens 3.30-11pm, Tues-Sun and a dip costs ¥300 (£1.60).

So bathing is about more than getting clean. It's the perfect way to soak up a sense of ancient Japanese culture?

Yes. The mountain hot-springs town of Naruko Onsen in Miyage prefecture is best known for its crowning glory, Taki-no-yu (00 81 229 83 3441), a fabulously atmospheric wooden bathhouse. The latter has hardly changed in 150 years and continues to draw onsen aficionados from across the globe for its curative waters packed with sodium chloride and sulphur. It opens 7.30am-10pm daily and a dip costs ¥150 (£0.80).

I've heard some onsen have outdoor pools and mixed bathing. Is this true?

The Zao Onsen (local tourist information 00 81 23 694 9328) in Yamagata prefecture, a 40-minute bus journey from Yamagata's JR station, is a prime example of a panoramic cherry blossom vista from the outdoor hot tub. Its 200-year-old dai-rotemburo (trio of outdoor pools) can hold up to 200 people and feels unashamedly traditional with the smell of sulphur coming off the water and a host of aged regulars lolling around in yukata (gowns). It opens daily 6am-sunset and a dip costs ¥500 (£2.70). Alternatively, Nyuto Onsen near Lake Tazawa in Akita prefecture is home to Ganiba Onsen Ryokan (00 81 187 462 021), a mixed-sex rotemburo (outdoor pool). It opens 8am-6pm daily and costs ¥500 (£2.70).

All this bathing sounds great but where do I stay and eat?

Most onsen resorts have a traditional Japanese ryokan (guesthouse) nearby. These B&B-style places are often small, friendly and family-run. They offer traditional-style accommodation and often provide excellent home-cooked food for dinner and breakfast. Expect to pay around ¥5-7,000 (£27-£35) per person, per night, including two meals.

Right, I'm off for a good scrub then. Where can I get more information and do any UK tour operators offer tours?

For details of onsen, contact the Japan National Tourist Organisation (020-7734 9638; www.seejapan.co.uk). JR East runs an English-language train information line in Japan (03-3423 0111; 10am-6pm daily). For details, check the JR East website at www.jreast.co.jp. The Oriental Caravan (020-7582 0716; www.theorientalcaravan.com) has 14 nights in Tohoku visiting several onsen for £1,695, on a twin-share basis, excluding flights. The next tour starts on 5 October 2003. More information from: www.theorientalcaravan.com/pages/tohoku.htm.

David Atkinson is one of the authors of the new edition of Lonely Planet Japan (Lonely Planet, £15.99), out this summer.