The Nakasendo trail is one of the old 5 routes that connected Edo (today’s Tokyo) and Kyoto. It takes about a month to do the whole trail, maybe more depending on your speed to hike. We only did the Kiso Valley part. Most travel guide books and agencies talk about the Magome-Tsumago part and suggest to stay in 10,000yen Ryokans (Japanese inns) While it is worth considering spending a night in a Ryokan at least once during your stay in Japan (or in your lifetime), we did not have the money to do so for 10 days, so we did the trail the old way: camping. This however, proofed to be difficult for me (lets say I was spoiled during my life as a hiker in Europe): Japan does not have as many campsites scattered everywhere like you can see in France, Germany or even Switzerland. Finding a camping spot in strategic places when everybody goes to Ryokans was quite difficult but not impossible. We fortunately bought maps of the area and we spotted some campsites and mountain lodges that are open to hikers from spring to fall. If you plan to do this trail, don’t forget your maps (and your bell as there are bear warning signs everywhere)!
The most famous towns in this trail are Magome and Tsumago. If it is true that these two towns are astonishing, there are as well many little towns on the way that travel guides seem to have forgotten to mention or give very little credit to them. Kiso-Fukushima has lost most of its “Edo charm”, nonetheless, there are still some areas that have been preserved (perhaps reconstructed) and are worth to give it a little tour. My favorite was Narai. This town seems to have more authenticity and you can very well picture the samurais passing by the main street of this place. However, if you expect to find the whole Nakasendo trail as it was during the Edo period, you might get disappointed. Today you can very well see parts of the old path, but a lot of it has been erased or parts of the trail are pavement roads. Not to mention that the Chuo railway goes through the whole Kiso valley, “killing” a bit the antique atmosphere. This said, the mountains and the natural scene make up for everything.
If you don’t have a month to spare, you can always hike parts of it and cut others by train. For more information, contact the tourist office in each town, they were very helpful, or send me a message; I’ll be happy to suggest itineraries, restaurants, etc.
Here are some websites:
http://www.japan-guide.com/e/e6075.html
http://www.japan-guide.com/e/e6078.html
http://www.jnto.go.jp/eng/location/topics/nagano/jnto/83dn3a000000dppf.html
very useful site: