Running beside the central Japan Alps the Kiso Valley long has had travellers since before the Edo Period when people would walk the Kisoji though this later formed part of the Nakasendo connecting Tokyo and Kyoto. Due to the many trips on foot post-towns began appearing as rest points for travellers, many post-towns are still well preserved and attract visitors. The Kiso Valley is one of the best places to visit to experience rural japan.
Covering land in both Gifu and Nagano, this area was once a section of the old Nakasendō Highway, one of Japan's historic transport arteries joining Kyoto with Edo (present-day Tokyo). Roughly following the Kiso River, the once-important post towns now where travellers would stop form a well-preserved living museum of the Edo Period, with most modern facilities being hidden from sight. Historically, Kiso district was once known as Nishichikuma District (西筑摩郡).
The centrally-located train station for the Kiso Valley is Kiso Fukushima (木曽福島), located on the JR Chuo Main Line.
There are several different approaches to Kiso-Fukushima from Tokyo. One route is to take the Tokaido Shinkansen Nozomi to Nagoya, then transfer to the Wide View Shinano for the run to Kiso Fukushima (3 hours 20 minutes, ¥13800).
Another route is to take the Nagano Shinkansen Asama to Nagano and transfer there to the Wide View Shinano. This takes about 3 hours 40 minutes and costs ¥11300.
If you use the Japan Rail Pass, you should go via Nagano or Shiojiri.
Note that some other parts of the valley are located at other stations near Kiso Fukushima on the JR Chuo Main Line (see below).
Buses of the following two companies serve part of the valley and are good for train connections and returning to your destination after a hike, although they run infrequently.
The biggest attraction in the Kiso Valley are the picturesque post towns that follow along the Nakasendo. The two most visited and best preserved are Tsumago and Magome near the south of the valley. Post-towns developed in the Edo Period as a rest points for travellers walking from Tokyo to Kyoto due to laws in place making this the only way to travel. Most post towns had a Honjin that served as the main inn and smaller Wakihonjins that served wealthier travellers, Tsumago and Magome both have restored Honjins.
The Nakasendo, an old route connecting Tokyo and Kyoto runs through the Kiso Valley and one could walk the entire valley from Nakatsugawa in the south to Shiojiri at the valley's northern end. The most popular section of the route is the trail from Magome to Tsumago due to the cobble stone path connecting the cities and the route's gentle nature on other sections of the Nakasendo one will have to walk on the sides of roads for most of the journey.
The Kiso Valley's main speciality are it's soba and Goheimochi, grilled mochi with sauce. Soba in the Kiso Valley is traditionally made with water from the Kiso River they are usually eaten with locally produced Sunki (red turnip) pickles or dipped into various vegetable broths, although soba is eaten all year round the pickles are most common during winter. Various Wagashi (confectionary) shops can be found in the Kiso Valley usually using the area's chestnuts. Due to the area's popularity many western-style cafes and restaurants can be found in the region specifically in Tsumago and Magome. Most restaurants in the smaller post-towns close down at night, if you're staying up late you may want to have your own food or contact your accommodation for meals.
The Kiso valley is known for the "Hinoki" fine-grained cedar pine trees (Chamaecyparis Obtusa). This scented wood is known for its durability. Hinoki is used for example for bath tubs and accessories. Japan's most important shrine, Ise Jingu is rebuilt each 20 years using Kiso Hinoki. You can buy Hinoki goods, especially around Narai. Kiso-Hirasawa in Shiojiri is famous for its lacquerware.