A pretty small, well-maintained cave. I had no luck seeing a live bat, but they have a museum outside where you can check out the anatomy of the creature. Make sure to wear footwear with grip, since some portions are slippery.
Loved it, walk thru un guided, looks super muddy but it's just the way the rock looks when wet, head room get super low on the full route for a short time,but there is an easy route,well worth it, takes about 1 hour door to door, had a blast
Located in Aokigahara Forest near Lake Saiko, the Saiko Bat Cave is the largest lava cave formed by the eruption of Mount Fuji in 864 AD. The cave extends approximately 386 meters in total length and features several chambers and corridors with varying ceiling heights. It is part of the “Fugaku Wind Cave – Narusawa Ice Cave – Saiko Bat Cave” trio of lava tubes, all created by the same ancient lava flow.
The cave’s name comes from the bats that used to inhabit it, primarily the Eastern Bent-Wing Bats. However, the population has significantly decreased due to temperature fluctuations and human activity, and the cave is now mostly a geological site rather than a wildlife habitat.
Inside, visitors can observe fascinating natural formations such as lava ledges, lava shelves, and diatomite layers, which indicate the prehistoric water levels of the ancient Sea of Se-no-Umi. The cave’s temperature remains around 10°C (50°F) throughout the year, making it cool even during summer.
Illuminated pathways and safety railings make the route accessible, though some passages are narrow or require bending down. The cave tour takes about 15–20 minutes, and informative signs in Japanese and English explain geological features.
The bat cave is really cool and it's kind of nice to be able to go in a cave on your own and walk around. Please be mindful of the bats and quiet while you're walking around. You do have to get pretty low in some spots so definitely make sure you're wearing your helmet and be prepared to maybe get on your hands and knees. It is a little cold in the cave but it's nice in the summer. There's a bus stop out front and you can easily walk to the other caves from here
It’s very cool learning about how these caves were formed over thousands of years from the volcano. It’s probably not the best place to go if you’re claustrophobic. You’ll be squatting and walking for some distance. It’s cooler in the cave which was an amazing break from the blaring sun. Tickets are 350 yen and we were in and out in about an hour since we checked out the free museum (all in Japanese) and gift shop. The museum was interesting to learn about the fish conservation acts in Lake Seiko. Very helpful gentleman helping us during our time here despite the language barrier.
