There are Onsen trail that has the line of Onsen water. The trail takes about 1 hour and offers great view of the valley.
Seko Valley (世古峡) is one of scenic place in Izu peninsula. It is about 1km long with beautiful view of the river. It is also known as Koyo Spot. It has a nice Autumn leaves during the beginning of December.
Tourist Info.
There is parking. No restroom.
Access
0. at Shuzanji Station.
1. use local bus to Yugashima Onsen.
2. walk.
45 min
New Wave Samurai Movie. 
映画好き集まれ！ 
There are Onsen trail that has the line of Onsen water. The trail takes about 1 hour and offers great view of the valley.