A few weeks ago I took a weekend trip to a city south of Aizu with my girlfriend. We took a special sightseeing train, and got to sit in a train car with tatami seats. Pictured above is the train, and below is the interior of the train car we rode in.
The route that the train took was very pretty. We passed through several tunnels, and over many bridges.
Occasionally during the trip the train would stop in the middle of bridges so we could look outside. The line went through the mountains and over pretty rivers.
The train would also stop at some of the stations for a short time, and let the passengers get out and walk around. Above is a picture of one of the platforms. Below is a picture of a public bath attached to one of the stations. Here passengers can put their legs into the hot water while they wait for their train.
Me and my girlfriend only took the train to Minamiaizu, but it is possible to ride further south all the way to Tokyo. In Minamiaizu we went to a bakery, a museum, and a small shrine. There were many more things to see, so I hope go to back again.