Kinugawa is one of Japan's worst examples of development gone overboard: after a serious case of boom and bust, what was once a pristine mountain valley is now a graveyard of rusting, abandoned ferroconcrete hotels. Still, the town remains within fairly convenient striking distance of Tokyo and the Kinugawa River is as stunningly green-colored as ever. If you can spare the cash and time, it may be worth it head up northward to Kawaji, which isn't quite as overbuilt.
The name "Kinugawa" literally means Angry Demon River. The exact provenance is unclear, but the most likely explanation is that this comes from the raging waters within — although the river is now dammed and considerably more placid.
Kinugawa is most easily reached on the Tōbu Kinagawa Line (東部鬼怒川線) from Asakusa, Tokyo. There are occasional direct express trains (2 hours, ¥2800). Ordinary rapid trains are cheaper at ¥1500, but will require at least one change at Shimoimaichi. Kawaji is another 20 minutes up the line.
There is no direct JR access, although you can take the Shinkansen to Utsunomiya, change to the JR Nikko line for Imaichi, and then change again to the Tobu line for the final leg. This is unlikely to be worth the hassle even if you have the JR Rail Pass.
Kinugawa is fairly spread out. You can either use the infrequent buses, or the expensive taxis. If arriving by train, be sure to check if your lodgings are closer to Kinugawa Onsen or Kinugawa Kōen station.
Aside from the mountain valley itself, there is little to see here. The Nichien Momiji Line, the highway connecting Kinugawa and Kawaji, makes for a fairly scenic drive though.
Loll about in hot springs. More adventurous types may also want to try battling against angry demons by rafting in the Kinugawa River.
Most guests eat at their lodgings, but there are a scattering of restaurants just outside Kinugawa Onsen station.
The recession of the 1990s hit Kinugawa hard and many hotels struggle with low occupancy rates (or have been outright shut down). This means there are some pretty good bargains to be found, especially off-season.