More than 90% of Japan is mountains and forest which make great valleys for hiking. Especially, during autumn, you can enjoy great Koyo. Entire mountain will be turn into red. In summer, it has great green leaves and flesh water.
Nishizawa Valley (西沢渓谷, nishizawakeikoku) is the valley of Fuefuki River(笛吹川) located in north Yamanashi. It is a part of Chichibu-Tama-Kai National park(秩父多摩甲斐国立公園). There are many mountains around the valley, and the valley itself has great hiking course, takes about 4 hours), with the beautiful waterfalls including Nanatsugama-Godan Falls which is one of the 100 best waterfalls in Japan. Green leaves are very beautiful after the season of cherry blossom, and also the autumn leaves are excellent.
Tourist Info.
There are many fee parking around the entrance of hiking course. Their you can get a maps of the hiking courses. The sidewalk of the river is well constructed, so even it is hard river, you can enjoy walking without any heavy duty tracing stuff.
Access
0. at Yamanashi shi Station.
1. use Shiei bus to Nishizawa keikoku
3 hr. 20 min
New Wave Samurai Movie. 
映画好き集まれ！ 
