Gendate Valley (厳立峡) is located Osaka, Gifu Prefecture. The entire valley was formed by the lava of Mt. Ontake. It is popular hiking courses which you can enjoy waterfalls. Gandate Rock which located at the entrance of the valley is Natural Monument of Japan.
Tourist Info.
There is a parking and restroom.
Access
0. at Takayama Station
1. use JR Takayama Line to Hida Osaka (32 min.)
2. use taxi or bus to Gandatekoen
1 hr.
Let's learn MJER Iaijutsu. 
映画好き集まれ！ 
Gandate Valley is also known as Mitsu Falls' Courses which is one of 13 hiking and sightseeing courses of Osaka Waterfalls.
Waterfalls
Mitsu Falls
Karatani Falls
Aganetoyo Falls
Mitsu Falls' Course
Guide: Not required.
Level: Beginners Course.
Time: Three hours.
Official Web Site of Hida Osaka 200 Waterfalls: http://www3.ocn.ne.jp/~osk200tk/