Spiritual salvation in Kumano has long involved plenty of blisters.

As we ascended a 12th-century stone-pitched footpath through mossy forests Brad, my hiking companion, told me about the ancient Yamabushi who used to test themselves in these mountains.

“They’d march through winter, eat little, and chant mantras,” he said. “But if they became sick and slowed the others down, they’d be expected to hurl themselves off the nearest cliff.”

This was going a little too far.

Yet ever since the 8th-century, pilgrims have endured many hardships seeking out a trio of grand shrines hidden deep in the Kii Peninsula forests on Japan’s Honshu Island.

The shrines grew from the worship of local forest spirits and the region of Kumano became renowned all over Japan as the place to find eternal salvation.

Pilgrims, from emperors to peasants, hiked from Kyoto for 40 days using footpaths known as the Kumano Kodo, to worship at the three shrines.

These days, Kumano retains its mystique and offers a rare glimpse into the spiritual and historical underbelly of the most advanced technological society in the world.

The Japanese still come to worship here, albeit mostly by coach.

But for the adventurous, the network of ancient footpaths has scarcely changed in a thousand years, and you can spend weeks hiking between the grand shrines, enjoying hot spring onsens and traditional inns serving delicious food en route.

It took me half a day to reach Kumano from Osaka by high-speed train.

Journeying down Kii Peninsula’s coastline was wildly pretty: canopies of emerald forest jutted into black sandy bays fringed by a cobalt-blue ocean.

The grand shrines were striking. I first visited Hongu Taisha: a 9th-century shrine rebuilt after a flood in 1891.

Its immense 34m red-lacquered torii (gate) can be seen kilometres away and draws coach-loads of Japanese visitors.

The beat of a thunderous drum, clouds of incense, and the clanging of bells rung by devotees before an open-fronted hall with a trimmed bark roof created a frisson of excitement.

The shrine priests were almost as colourful as the shrine, clad in mint-green and white robes with black-lacquered clogs and hats that resembled fruit pastilles.

For my first few days I walked a few shorter sections of the Kumano Kodo and invariably followed the paths with ubiquitous onsens where I could stop for a dip along the way.

The River Kawayu onsen was quite superb.

The river bubbles with luxurious warm water and bathers dig small shallows in the gravel to enjoy a very public bath.

I wandered down to the river in the yukata robe I had borrowed from a nearby local ryokan (inn), where I had stayed in a traditional Japanese room with a futon mattress spread across straw tatami floor mats.

After my soak, I sampled kaiseki ryori.

These intricately prepared meals are worth the splurge.

The individual dishes are sculpted works of art: from delicate raw fish and miso soup to tempura prawns and beef boiled in a sesame sauce.

Food had never tasted better.

This prepared me perfectly for a full day’s hike between the grand shrines of Hongu to Nachi.

We began at 5am for a 12-hour journey on one of the Kumano Kodo’s toughest sections known locally as Nakahechi.

Breaking dewy cobwebs across the trail, Brad and I hiked up mountainsides thickly forested with maples, camphor trees and leviathan cypresses strung with lichen trailing like old men’s beards.

The drums of Hongu drifted on the wind.

There were lots of ancient reminders of the trail’s halcyon days.

We passed oji (small shrines dedicated to forest deities), poetry-inscribed pillars, and dilapidated teahouses that once revived weary pilgrims.

It was hard going.

An ascent up ancient stone steps beyond Koguchi village made me breathless; the slippery descent afterwards left my knees begging for mercy.

When we eventually hobbled into the magnificent Kumano Nachi Taisha shrine just before dark, I sensed something of the awe generations of pilgrims would have experienced on their arrival.

Nachi is not only a Shinto shrine but is also located besides a magnificent Buddhist temple, in which (after a night’s sleep at the monastery lodgings) we attended a morning ceremony given by lime green-robed monks.

The temple was inspired by the nearby Nachi Waterfall, which at 133m is Japan’s highest. Yamabushi, explained Brad, immersed themselves in its freezing waters for purification.

But for me, nirvana represented a hot onsen bath and a delicious temple meal.

Japan’s great outdoors

Dive Okinawa

Subtropical seas of Japan’s southernmost Ryukyu archipelago make for great diving. Snorkelling and sea-kayaking (pictured left) are also highly recommended.

Shimanami sea cycle

A bizarre yet fun cycling route takes bikers across the inland sea, hopping between Honshu and Shikoku Islands via massive suspension bridges. I cycled the 77km trip in a day but it’s more relaxing to take two. See kancycling.com/shimanami.

Climb Mount Fuji

Scaling Mount Fuji (3776m) can only be undertaken between late July-late August. Organised two-day summit trips start from £120. See hisexperience.jp.

Snowboard hokkaido

There’s awesome powder on Hokkaido Island in November-April. Soak in an onsen after a day on the slopes. See seejapan.co.uk/winter.

Shinto in a nutshell 

To outsiders, Japanese Shintoism is shrouded in mystery because it bears little resemblance to organised religions we’re used to.

Shintoism pre-dates Buddhism in Japan (which arrived around AD550) by many centuries.

It has no single all-powerful god, just thousands of local deities inspired by nature; no single holy place like Mecca, but thousands of public shrines; and there is no definitive spiritual text like the Bible, but written stories about the exploits of deities.

Roughly translated, Shinto means ‘way of the gods’.

It reveres natural objects, believing anything from trees to rocks possesses a spiritual nature.

When visiting a typical Shinto shrine you’ll pass through the torii gate, which represents crossing into the realm of the gods.

Pilgrims wash their mouths and hands in a fountain before entering.

Worshippers then stop before open-faced halls, ring a bell to wake the spirits, bow twice, drop money into an offertory box and clap several times before withdrawing for the inevitable photo.

Some purchase a small wooden tablet, an ema, and write a wish to bring good fortune.

More for your yen 

There is a lingering perception that Japan is prohibitively expensive. Sure, it’s not dirt cheap, but once you’re there it can be done on a reasonable budget without compromising the experience. Check out japan-cheap-travel.com for tips.

FOOD

It’s easy to eat cheaply and well in Japan for as little as £5-£8 per meal.

TRAVEL

If you’re planning to travel extensively, invest in a JR (Japanese Railways) rail pass. See japanrailpass.net.

ACCOMMODATION

Youth hostel dorms are around £20 per night, but consider the greater authenticity of Japanese-style accommodation such as minshuku (B&Bs) or ryokan (inns): They can start from around £25-£50 per night. See ryokan.or.jp. Coffin-like capsule hotels for those untroubled by claustrophobia start at around £20 per night.