Deep in the lava forests on the western foot of Mount Fuji there is a cave formed when molten rock flowed down the slopes and its crust cooled while the interior drained away. The Hitoana lava tube is small and low, but in the sixteenth century an ascetic called Hasegawa Kakugyo is said to have practised extreme austerities inside it, and he became the founder figure of the Fuji-ko, the popular confraternities whose members climbed Fuji as an act of worship. Around the cave entrance stand hundreds of stone memorials erected by Fuji-ko groups over the centuries, mossy and leaning among the trees. The site is one of the components of the World Heritage listing Fujisan, Sacred Place and Source of Artistic Inspiration.
The cave sits on the Asagiri plateau, a high grassland and dairy region between Fuji and the mountains to the west, where cows graze on open pasture and the volcano fills the sky on clear days. Fresh milk and ice cream are sold at farm shops along the roads, and the light in the early morning, when Fuji turns pink, is magical. Clouds often hide the summit by midday.
Riding here is a joy. Route 139, the main road running north from Fujinomiya around the west side of the mountain toward Lake Motosu and the Fuji Five Lakes, is wide, smooth and flowing, with gentle curves and constant views of the volcano. Smaller roads wander across the plateau through farmland and forest. Japanese traffic is orderly, but speed limits are low and enforcement strict. Weekends can be busy with tourists. Winter brings snow and ice at this altitude, around seven to nine hundred metres, so spring and autumn are best.
Fujinomiya, sixteen kilometres away, is the main town, with fuel, shops and the Fujisan Hongu Sengen Taisha shrine, the head of the Sengen shrines dedicated to the mountain's goddess. The town is known for Fujinomiya yakisoba, fried noodles with a chewy texture, sold everywhere. Fujikawaguchiko, on the north side of the mountain, is another base.
The cave itself is accessed via a small park, and entry into the tube may be restricted; the memorials and the forest are worth the stop regardless.