A large part of Fukushima prefecture is covered with mountains naturally leading to a lot of streams and rivers as well. Japan is making use of these natural sources to create electricity using dams. An example of this is Ouchi Dam which is south of Aizuwakamatsu city. The road leading to this dam from Aizuwakamatsu as well as the lake created by making the dam are enjoyable driving roads.
The road leading to the dam from Aizuwakamatsu is the route 131 also known as Shimogo Hongo Line. The good part starts around 15 minutes driving south from Aizuwakamatsu. After a long, quite flat straight, the road takes a left turn around some buildings. From here on the road starts climbing towards the Ouchi Dam. Wide lanes, good road quality and a large amount of corners ensure a lot of driving pleasure. Around 6 kilometers later there will be a tunnel which is the entrance to the lake near the dam. Continuing for a minute or two on the route 131 will let you reach the Ouchi Dam.
At both ends of the dam there are stopping places. In case you are in the mood for some more driving, you can make a round around the lake. The west part is quite narrow but very curvy. In the winter there is a possibility for seasonal closure on this part though, so driving around the lake is not possible then.
In general, there is not much traffic on this northern part of the Shimogo Hongo Line as well as the road around the lake. However, on weekends and holidays it can be busy with tourists as there is a popular attraction close to the dam, called Ouchi-juku. Also worth visiting if you are in the area already.
Google Maps location link:
Ouchi Dam
JDM4all Youtube video: