IYA VALLEY, Japan - The Japanese know the Iya Valley for its remoteness, alpine scenery, and vine bridges, and for being the fabled 12th-century refuge of the Heike clan. Americans are unlikely to know it at all, but if they do, it's probably because of Alex Kerr.

At the tourist information office near Tokyo Station, I tried to explain this to the two nice women behind the counter. They were visibly surprised that a foreigner was planning to visit the valley nestled in the mountains of Shikoku, the smallest of Japan's four main islands.

Kerr, a writer whose study of Asian languages and culture began as a 9-year-old in Bethesda, Md., discovered the Iya Valley in 1971, when he was a college student. He soon bought an unoccupied farmhouse there and renovated it, painstakingly restoring the thatched roof. He named the place Chiiori, or "House of the Flute."

I gave a brief account of this, which I'd read about in Kerr's 1996 book, Lost Japan. The women smiled and shook their heads, as though this were the sort of thing only Westerners could possibly know about. Then they handed me two brochures produced by the area's tourist boards. On the cover of one was a picture of Chiiori.

Visiting the Iya Valley last summer, I didn't make it to Chiiori. It's far off the main road and is now a rather expensive hostelry, managed by a nonprofit group Kerr founded. But I was glad to see that picture, just to prove that someplace in the region I'd read about actually existed. I'd found little other evidence that there was anything there, except the history reflected in the name Iya Valley, which means "Ancestor Valley."

In the age of crowdsourced data, there's little uncharted territory. Yet last year, Google Maps showed nothing in most of the Iya Valley, save mountains, the Iya River, and a few twisting roads. (Cursory information on a few more places has been added since, but the map is still largely empty.) When I arrived at Oboke, the closest train station, I had only a vague sense of what awaited me.

In Japan, where all notable things are grouped in trios, Iya is one of the "three hidden valleys." Still, it's not exactly the South Pole. Trains arrive at Oboke almost hourly from dawn to midnight, and a pair of tag-team buses can traverse the entire basin in about two hours. But the buses don't make the complete trip in winter and run only on weekends most of the year. The longest period of daily service is from mid-July to the end of August.

There are frequent runs from Oboke to Kazurabashi (which means "vine bridge") at the west (nishi) end of the Iya gorge. It's a touristy area, with shops, restaurants, and - most egregiously - a large parking deck jammed against one side of the ravine. Away from the road, the view is more rustic, although the 148-foot-long vine bridge is crowded with people who move gingerly from slat to slat, clinging to the vines that hold everything together - or appear to - 46 feet above the river.

According to local lore, Heike warriors (also known as the Taira) strung bridges made of vines that could be severed quickly to prevent their enemies from pursuing them. These days, though, the tendrils wrap around steel cables. The same is true of the three other vine bridges, all of which cross the same bend of river near the opposite end of the valley, in the area known as Higashi ("east") or Oku ("deep") -Iya.

The valley and surrounding mountains combine traditional Japanese attractions - regional delicacies and hot-spring spas - with ones that can be found much closer to home: hiking, camping, and white-water rafting in warm weather, leaf-peeping in fall, skiing in winter. Although the highest peak, Mount Tsurugi, is gently sloped and a mere 6,413 feet, the tightness of the Iya gorge provides dramatic vistas suggestive of loftier climes. The sense of enclosure renders the terrain mysterious, which may be why Japanese accounts of the valley - such as The Tale of Iya, which screened at the D.C. Environmental Film Festival this year - tend toward the fanciful.

Nishi-Iya is as far as most visitors get, because beyond there, the road is often reduced to a single lane. Large mirrors are positioned at the turns, and bus schedules must accommodate a fair amount of backing up and pulling over to let vehicles pass in the other direction. I saw no Westerners past Kazurabashi; my fellow passengers were mostly locals, including two teens in school uniforms, and some hardy, silver-haired mountaineers outfitted with the latest hiking gear.

Between the west and east bridges are several farm villages, none apparently thriving, with a handful of shops, post offices, and restaurants. Kyojo is home to most of the businesses, and Ochiai has thatched houses (a few restored as guesthouses), a Shinto shrine, and an eatery that serves soba, the noodles made from locally grown buckwheat, and teaches how to make them.

Kubo, where a transfer to the twice-daily municipal bus is required to continue into the deep, had no evident commerce. Even the beer-vending machine was abandoned. There was one reminder of urban Japan's kawaii ("cute") culture as we chugged east: Coming from the otherwise staid bus driver's cellphone, I could hear, "Heigh-ho, heigh-ho, it's off to work we go."

Rural Japan is losing population, and traditional agriculture is waning. In Iya, the decline has inspired a guerrilla-art project. The second hamlet past Ochiai is Nagoro, where humans are outnumbered by life-size upholstered figures. They sit and stand all along the main road and sometimes well off it. These mute villagers fish, ride tricycles, chill in recliners with their shoes off, and wait perpetually at the bus shelter.

Scarecrow Village was created by Ayano Tsukimi, an artist who grew up in Nagoro and moved back there about 15 years ago. Struck by how empty her hometown had become, Tsukimi began to repopulate it with these padded people. She hasn't commercialized the project in any way, which is somewhat surprising in souvenir-happy Japan. There are no Scarecrow Village mugs or T-shirts, but, then, Nagoro doesn't have even a grocery store or cafe that could peddle them.

From Nagoro, I walked toward the Oku-Iya vine bridges, a mostly uphill hike. There's a dam just beyond the town, and I spied a few men in industrial apparel. More than once, though, the workers turned out to be stuffed.

The twin kazurabashi at this end of the valley are known as the Niju ("double") or husband-and-wife bridges. The "manly" crossing is the higher, scarier one. There's also a third way, a vine bridge that carries a rider-propelled cart; it's called yaen, meaning "wild monkey," because the vehicle supposedly lurches savagely as it crosses. But I watched as a woman and a young boy crossed, and it seemed a gentler passage than the vertiginous one across the husband bridge.

The Iya flows freely at both ends of the valley. This is rare in Japan, which has encased most of its rivers in concrete. But Oku-Iya is more picturesque than Nishi-Iya, and its vine bridges are in a forested area that's secluded and serene. Even with kids splashing in the river and scampering up the rock staircases, this was perhaps the most peaceful place I've been in Japan.

There's a fee to enter the bridge area, but no businesses beyond there. Across the road, a gift shop offered souvenirs and soft-serve ice cream in a half-dozen flavors, including soba. (I went for vanilla.) Aside from a campground across the river, there's little else except those exemplars of Japanese civilization: drink-vending machines and well-kept public bathrooms.

The second and final westbound bus leaves the Oku-Iya vine bridges about 3:30 p.m. Because I wasn't packing a tent or sleeping bag, I needed to be on it. I regretted my early departure, but shortly after the Kubo transfer, an afternoon storm arrived. The sun vanished, the sky closed in, and rain raked the bus all the way back to Oboke.

Iya now felt like the Colorado Rockies, albeit at half the elevation. Mists nearly filled the narrow chasm, obscuring much of the one-lane road and nearly all the mountains. Suddenly, the valley looked like the kind of place where someone, or even a whole clan, could just vanish into the landscape.