Not far from Kobe. You can walk over Rokko Mountain, if you want to go that way. This is a hot spring town but, if you are not into baths it is still a good walking place especially in winter when you will probably have snow. There are a number of ways to get to Arima. Bus from Kobe, or take the Kobe subway to Tanigami and change there for the Kobe Dentetsu Line for Arima-onsen. You may have to change at Arimaguchi. Or you can take the rope way across Rokko and down the other side.
While you are at Nikko keep on going. A short bus ride up a very winding road is the town of Chuzenjiko Onsen. A real Japanese tourist spot in season. If you go there out of season it is empty, so stay away from Japanese holidays. This is a really beautiful spot for nature lovers. Lakes, riverse, waterfalls, lots of trails in the woods. Most hotels will have hot spring baths.
From Nikko, take a bus going to Chuzenji or to Yumoto Spa. Get off at Chuzenjiko Onsen. Right there will be Kegon Falls and a rope way to a good view of the mountains and lake. The falls are wonderful. From the bus stop you can go right or left around the lake. If you go left you will pass hotels and restaurants and eventually come to a shrine. Keep following the shore of the lake and pass summer houses of various countries. If you go to the right you will pass hotels and restaurants but once out of town you can walk forever. Pick up the “Salamander Trail” (I actually saw one!). This will take you right along the shore of the lake until you come to a ferry boat landing. From there follow the highway and on the right you will come to another waterfall. Follow the river upstream along a very delightful trail. You will come to an area that opens up into a mountain meadow. Beautiful views of the surrounding mountains. Flowers everywhere, in season. Eventually there will be another waterfall with some shops at the base. Walk up the right side of the waterfall and you will come to another lake. Stay to the right and you will come to Yumoto, just a collection of hot spring hotels. Look for the temple and you will find a swamp with hot springs. This is a long walk but very easy going. Give yourself about five hours, including many stops to eat and take photos. Then take the bus back to Chuzenji or Nikko.
If you want to get away from it all, this is it. Not far, but certainly out of the way. This trip is to Shikoku. Take the Shinkansen to Okayama and change to the train going to Awa-Ikeda, described elsewhere. At Awa-Ikeda station take a bus to Iya Onsen. The bus stop is across the street right next to a big map. (¥ 1000). You will be on the bus for about an hour. It will stop at Iya Onsen which consists of a hotel (expensive) and a rope way down to the river and onsen proper. Even if you are not a lover of hot springs this is worth the trip. At the bottom there are the baths, outside right next to the river in a deep gorge. The water is not super hot and very silky, a great place to sit. There are places to walk, bridges to cross and places to have a picnic.
From the onsen you can continue on by bus (they are not too frequent) or you can walk. After a very pleasant walk (all slightly downhill) of about 3 hours you will come to Kazurabashi which is a bridge made of vines. No big thing, and there is a nice concrete one next to it. There are some inns and this is a good place to spend the night.The next morning you can reverse the trip or continue on to Oboke. To get to Oboke, take a bus (be careful – there are only three a day and the first leaves at 7.30 am). Don’t worry about getting up on time because there is a very loud air raid warning at 6.00 am. The bus will take you up into the mountains and back down again; about an hour. At Oboke there is a boat ride to Koboke and back which is worth it. At Oboke you can get a train back to Awa-Ikeda. They run about every 2 hours.