Lake Saiko () is smaller and much less developed than neighboring Lake Kawaguchiko. The views of Mount Fuji from Lake Saiko's shores are blocked by other mountains, except at the lake's western end from where there are beautiful, full views of the volcano.
Lake Saiko is surrounded by wooded mountains and a few camp sites, and is a popular destination for those interested in camping, boating, fishing and other outdoor activities. A network of hiking trails covers the mountains and hills surrounding the lake, as well as Aokigahara Jukai, an expansive forest south of the lake, infamous as a suicide spot and for people getting lost.
Several caves, formed during past eruptions of Mount Fuji, can be found around Aokigahara Jukai in the vicinity of Lake Saiko. Three of them, the Ice Cave, Wind Cave and Bat Cave, have been developed to be easily accessible to tourists. The area is also known for its autumn colors which are usually at their best around the first half of November.
Iyashi no Sato is a mixture between open air museum and craft village, built in the style of a traditional village with thatched roof farmhouses. Visitors can try their hand at or purchase different traditional handicrafts and learn about the local history and traditional lifestyle.
Koyodai
Hours: 8:30 to 17:00 Closed: When there is a lot of snow Admission: 150 yen
Koyodai is one of the smaller mountains south of the lake, which is famous for and named after its autumn colors (koyo). The Koyodai is accessible in an easy 30 minute hike from the nearest bus stops, and offers excellent views of Mount Fuji from a paid observation deck. It is also accessible by car via an unpaved road.
Yurari•
Hours: 10:00 to 22:00 Closed: No closing days Admission: 1300 yen (1500 yen on weekends and national holidays)
Yurari is a modern, beautifully designed public hot spring facility with a variety of gender segregated indoor and outdoor baths. The baths on the second floor have nice views of Mount Fuji. Private baths with views of the mountain are also available (50 minutes, 1700 yen).
The Bat Cave, named after its former winter inhabitants, is the most extensive of the three caves. In total the cave is nearly 350 meters long and has multiple large chambers and diverging tunnels to be explored. Some of the tunnels come with rather low ceilings.
Even during the summer, the temperature in the Ice Cave usually stays below freezing. Consequently the cave has been used since the early 1900s to store ice for use around the year. The circular walk through this cave is not very long, but contains passages with low ceilings and slippery stairs.
In the past, this cave was used as a natural storehouse and refrigerator, as the temperature inside stays at a relatively constant zero degrees Celsius throughout the year. The cave is furnished with a few shelves that store boxes of acorns and silkworm cocoons. It is the most easily walkable and least exciting of the three caves.
Access
The Omni Bus Green Line (or Saiko Line) connects Kawaguchiko Station with Lake Saiko, circles the lake in a clockwise direction and stops at Iyashi no Sato, at the trailhead to Koyodai and near the three caves.
Apart from the omni buses, there are a few regular buses that operate between Kawaguchiko Station and Lake Saiko. Buses bound for Shin-Fuji and Lake Motosuko stop at the Fuji Midorino Kyukamura bus stop near Yurari Onsen (20 minutes, 520 yen) as well as at the ice and wind caves a few minutes later. There is one bus about every hour. A second regular bus line connects Kawaguchiko Station with the northern shore of Lake Saiko, stopping near Iyashi no Sato and at the bat cave along the way.
