Koyodai and Sankodai Observatory

A lava cave on the edge of Aokigahara with a cool interior and displays about its historic use as natural cold storage. Expect steps, wet surfaces and a large temperature difference from outdoors.

A forest park beside Aokigahara with bird habitat, walking space and a well-known winter ice-tree festival.

A dense forest growing over the 864 lava flow, best explored only on signed nature trails and official cave routes.

A forested outdoor resort beside Lake Saiko with tent sites, cottages and rental equipment.

The largest lava cave in the Fuji Five Lakes area, protected as bat habitat and explored using helmets along low natural passages.

A compact lava cave formed by a Mount Fuji eruption, with low passages, stairs and naturally cold interior conditions. Helmets and footwear guidance should be followed; this is not a barrier-free route.

A wooded campground on Lake Saiko offering a quieter lakeside base for paddling and Fuji Five Lakes exploration.

A reconstructed thatched-house village near Lake Saiko with craft experiences and views toward Mount Fuji. Its operator describes spring blossom, green summer, autumn color and snowy winter scenes; each depends on actual conditions.