The Nakasendō (中山道, "Central Mountain Route") is one of the two key historical routes that connected Tokyo (Edo) to Kyoto.
Understand
[edit]
Unlike the more famous coastal Tokaido, the Nakasendō travels further inland, passing through 69 post stations (宿 shuku, in suffixes -juku) along the way. The Nakasendo flourished during the Edo Period, as you only had to cross a few rivers, unlike the Tokaido. Many famous people travelled the route during the Edo Period, most notably haiku poet Basho of Narrow Road to the Deep North fame.
These days, while the Tokaido passes through Japan's most populated areas and has thus been transformed beyond recognition, the quieter, more remote Nakasendō, while hardly untouched, still retains a few stretches of the old road and some of Japan's best-preserved post towns, most notably the 8 km Magome-Tsumago Trail in the Kiso Valley.
Prepare
[edit]Get in
[edit]
If you're planning on doing the entire route, your starting point will be either Tokyo or Kyoto. However, if you're planning on visiting the most popular central bit in the Kiso Valley, you'll need to make your way to Nagoya and continue from there on the JR Chuo Main Line.
Go
[edit]
Unlike the Tokaido, which is more or less faithfully followed by the JR Tokaido Main Line and the Tokaido Shinkansen bullet train, the Nakasendo only has partial railway coverage, meaning having your own wheels is the best way to go if you intend to cover the whole thing.
By car
[edit]Although much of the Nakasendō no longer exists in its historic form, its route is now roughly followed by modern roads. In order, they are:
National Route 17
[edit]1 Tokyo to 1 Takasaki (Gunma Prefecture)
National Route 18
[edit]Takasaki to 2 Karuizawa (Nagano Prefecture)
National Route 142
[edit]Karuizawa to 3 Shimosuwa 
(Nagano Prefecture) (73 km)
An 8 km stretch of the old forest trail has been preserved between the post station at 1 Wada-shuku (#28) and the 2 Wada Pass (和田峠 Wada-tōge), at 1,600 meters the highest point of the entire Nakasendo.
At 22 km, the gap between Wada and 3 Shimosuwa-shuku (#29) is the longest on the Nakasendo, and nearly all travellers stopped at Shimosuwa to gather strength or recover with the help of the only hot springs along the road. Shimosuwa is a modern town now, but a number of hot spring hotels remain and so does the gorgeous Iwanami-ke Honjin.
National Route 20
[edit]Shimosuwa to 4 Shiojiri (Nagano Prefecture)
National Route 19
[edit]National Route 19 runs through the Kiso Valley from Shiojiri to 5 Ena (Gifu Prefecture).
The 80 km stretch from 4 Shiojiri-juku (#30) to 5 Midono-juku (#41) is a National Historic Site of Japan. In particular, 6 Narai (#34), once the largest and richest post-towns in the Kiso Valley, is worth a visit. Forking off from the Nakasendo at 7 Nojiri-juku (#40), the 16 km Yogawa Trail (与川道 Yogawa-michi) offers an alternate route to Midono, crossing the mountains to avoiding a frequently flooded stretch of the Nakasendo near the Kiso River.
Right after this is the best preserved and by far the most popular part of the Nakasendo, the Magome-Tsumago Trail (8 km) between the post towns of 8 Magome (#42) and 9 Tsumago (#43), with 10 Magome Pass marking the border between Nagano and Gifu. The trail is typically walked in the "wrong" direction starting from Magome, since otherwise you're going uphill for much of the way.
National Route 21
[edit]Mitake (Gifu Prefecture) to 6 Maibara (Shiga Prefecture)
11 Tarui was the 57th post station and the start of the 60-km Minoji (美濃路) shortcut to Miya-juku on the Tokaido, and has some preserved buildings. The 58th post station, 12 Sekigahara is famed for an epic battle in 1600 but little remains of the post station; even the honjin's gate was moved to Tarui.
National Route 8
[edit]Maibara to 7 Kusatsu (Shiga Prefecture)
At Kusatsu, the Nakasendo joins the Tokaido for the final stretch along National Route 1 to 2 Kyoto.
By train
[edit]From Tokyo, you can get to Takasaki via the Takasaki Line from Omiya (near Tokyo) to Takasaki and continue a bit further on the Shin'etsu Line to Yokokawa, where the train ends.
The easiest section to tour by train, however, is the central part in the Kiso Valley, where the JR Chuo Main Line more or less follows the Nakasendo from Suwa to Shiojiri to Ena. The Wide View Shinano limited express runs the length of the route from Nagano to Nagoya, and in the fall peak season, JR Tokai even runs occasional branded "Nakasendo Trains" from Nagoya to Narai.
At the western end, Maibara is on the Tokaido Shinkansen and there are plenty of trains through Kusatsu to Kyoto.
On foot
[edit]A few brave souls still walk the entire length, but it has long since been concreted over and traces of the old post road are few and far between.