Kiyotsu Valley (清津峡) is one of the 3 major Valleys in Japan. It is located in Tokamachi, Niigata Prefecture. The entire valley is about 12km long beautiful valley made by the lava flow.
It is registered as the national scenic beauty and natural monument of Japan. There is a tunnel that has great observatories.
Tourist Info.
There are parking and restroom.
Admission for the Tunnel: 600 yen for Adult, 300 yen for under highschool.
There is a group discount.
Time: 8:30 to 17:30 (Last entry 16:30)
Closed: From the middle of Jan. to the end of Mar.
The distance of the Tunnel: 750m
Pet allowed.
Access
0. at Echigo Yuzawa Station.
1. use local bus to Kiyotsukyoiriguchi.
2. walk 30 min.
600 JPY
1 hr.
New Wave Samurai Movie. 
映画好き集まれ！ 
Kiyotsu Valley is one of 3 major Valleis in Japan. It is about 12.5km long valley made from lava flow. It is one of the very popular Autumn leave spots in Niigata.
There is a tunnel that go into the rocks so that people can watch hard cliff of the valley. This tunnel has 4 observatories.
Each seasons has different sceneries. Especially, snow season is breath taking.
Official Web