Ōboke (大歩危) and Koboke (小歩危) mean, respectively, "big steps dangerous" and "small steps dangerous" — an apt description of the perils of traversing through these steep gorges on foot.
The Yoshino River which forms the Oboke and Koboke Gorges flows from Kochi Prefecture in the south up to the town of Ikeda to the north. Oboke is a bit larger and near the prefecture border, and Koboke is just to the north (its hard to really tell where one gorge ends and the other begins, as they more or less merge together.) The main access road of Rt 32 follows the river and runs entirely through the gorges from Ikeda to Kochi, and the JR Dosan train line also follows this route.
For lots of detailed information in English about Oboke, Koboke, and the neighboring Iya Valley, check the extensive IyaTime website, which also has lots of interactive maps and access guides as well as details regarding just about every place and provider in the area.
Rafting in the Yoshino River
It is recommended to travel in this area by car. If you get there by train, you'll have a long walk along a noisy road without sidewalks. It is also hard to find entry points for hiking trails without a car. Unfortunately, the nearest car rentals are located quite far away: Marugame, Takamatsu, and Tokushima.
National Highway 32 winds along the Yoshino River through the pristine valley. Coming from Osaka, Kobe or Tokushima, take the expressway and exit at Ikeda. Then follow route 32 towards Kochi for about 20 kilometers to Oboke.
A tunnel also connects Oboke to the western Iya Valley.
Both Oboke and Koboke have stations on the JR Dosan Line from Kochi to Takamatsu via Ikeda. Stops in Koboke are rare, though.
Buses go to/from the main Awa-Ikeda Bus Terminal in Ikeda through Oboke and Koboke and then on to the Iya Valley. Several additional buses go from Oboke Station to the the Iya Valley on weekends/holidays and less so during the week. For complete bus schedules in English through the area, check the IyaTime Bus Timetables.
See & Do
There's one big reason to visit: the rapids rushing through the gorge below. There are observation platforms on the highway and near the train stations if you're content to gaze from a distance, but more daring types will venture down onto the Yoshino River for a sightseeing cruise (¥2000 for a one-hour loop), and more adventurous types yet will try their hand at white-water rafting in the class 4 rapids. The rapids are Japan's biggest and most exciting, with amazing rock formations and crystal clear waters.
There are about a dozen rafting companies in the area, and most offer full and half-day rafting tours in English, and some also offer canyoning and other water sports. For a complete list in English of the rafting outfitters around here, check about "See and Do" section of the IyaTime website.
- Happy Raft, ☎ +81 0887-75-0500, . Arranges half/full-day rafting trips from ¥5500/10000 (cash only), mostly July 1 to September 30. English spoken. edit
If you survive the experience without developing acute hydrophobia, both Oboke and Koboke have onsen hot springs offering more bubbling water to soak in.
- Boke-Mart is a normal grocery store, but probably the best place to stock up before heading into Iya Valley. It's near JR Oboke Station.
Ikeda is the closest town with a real supermarket.
Eat & Drink
The local specialties are ayu and amego, delicious river fish salted and barbecued on a stick.
Sleeping in the area is useful for exploring the Iya Valley and surrounding towns, but is a bit far of the eastern end of the valley. If looking for hiking opportunities, lodging closer to Mt Tsurugi might be a good idea. For a complete list in English of places to sleep or camp in the Oboke and Koboke area, check about "Places to Stay" on the IyaTime website.
- Happy Guest House, Iwahara Otoyo-cho Kochi (1 min walk from Tosa-Iwahara station), ☎ +81 0887-750-500, . Overlooking the Yoshino River, four different guesthouses are on offer set in traditional-style homes, each with private rooms and self-contained kitchens. Very friendly staff will pick you up and drop you off from the train station and drive you to your guesthouse. You will need to bring your own food as there are no shops nearby or meals served. The owners also run a rafting company but you don't need to book a rafting trip to stay at the guesthouse (but lodging discounts are given for those who go rafting). ¥2500. edit
- Ku-Nel-Asob (空音遊 Kūneruasobu), ☎ +81 090-9778-7133, . A hostel set in a traditional farmhouse in Oboke — the name means literally "eat, sleep and have fun". The owner is friendly and speaks great English. The communal vegetarian meals that are served are highly regarded. It's located within an old-style hillside community and is a little hard to reach if without a car, but the view down into the Oboke Gorge is lovely. Bathing is done at a nearby hotel (free rides given), which has outdoor baths (onsen) that overlook the river. Free pick-ups given from Oboke Station. ¥9000 including dinner. edit
- Momonga Village Guesthouse (モモンガビレッジゲストハウス), ☎ +81 0883-86-2334, . Located in a tranquil side valley up from the Yoshino River and central Yamashiro, this hostel-style guesthouse is quietly set aside from the busier river area. The traditional Japanese interior and tatami (futon) beds makes it a very local experience. International staff can help explain things and the place is connected with one of the rafting companies if you are looking to get your river thrills. Though a bit inconvenient if without your own car, the homely relaxed feel of the guesthouse more than makes up for the location, and the travel information and options for getting around make sightseeing around the main attractions very doable. They offer pick up services to a few different bus stops depending on where you want to go. Offering both dorms (¥2500) and private rooms (from ¥3600), dinner and/or breakfast is available by reservations and snacks and drinks can also be separately purchased. BBQ services are also available (expensive, around ¥2000). With bike rental (¥500) and car rental (from ¥5000/day). Free WiFi and free parking. edit
- Iya Valley, with more scenic views and some great hiking too, is just across the tunnel from Oboke.
- Takamatsu - One of Shikoku's most interesting cities, with its castle and one of Japan's finest gardens, Ritsurin.
- Marugame - Small but charming castle city close by.
- Uchiko - Traditional merchant town with Kabuki theater and wax factory museum.
- Ozu - Site of one of Japan's most famous cat islands.
- Kochi - Far-flung city with its laid back atmosphere, castle, nature, scenic views, and one of Japan's best limestone caves close by.
- Uwajima - Rare sights like the phallus shrine, nice gardens, and bull sumo.
- Kotohira - Site of the famed Kompira Shrine, one of Shikoku's best and with beautiful views over the region.
- Okayama - Home to the beautiful Korakuen Garden, one of Japan's top three gardens, as well as the beginning of the Kibiji District Trail.