Kazahari is a high saddle on the border between Tokyo and Yamanashi, at around 1,150 metres, and the road over it is one of the quietest and prettiest in the Kanto mountains. It climbs from the Okutama lake country through dark cedar forest and then through deciduous woods that glow in autumn, with occasional views through gaps in the trees. The pass is narrow, with a limited number of corners where two vehicles can pass, and the surface is patchy, so a relaxed pace is the sensible choice.
The country around here is steep, forested and thinly populated. Villages are small, many houses stand empty, and the population has declined for decades as young people move to the city. Agriculture has been replaced by forestry, and the slopes are covered in planted cedar and cypress, with some old beech and oak woodland on the upper ridges. Springs run beside the road, and in places the mountains are covered in moss.
Otsuki, the nearest town of any size, lies fourteen kilometres away and has about thirty-one thousand people, with fuel, shops and restaurants. Uenohara and Itsukaichi are the other options, but they are further. A vending machine or a small shop may offer a drink, but do not count on a meal. A packed lunch is a good idea.
Weather changes quickly at this height. Fog is common, and in winter, snow and ice can close the road for days, so check conditions before setting out. In summer, the forest is cool and shady, a welcome relief from the heat of the plain, and thunderstorms can build in the afternoon. Falling branches and small rockfalls are not unusual after rain. Traffic is light, and in places you may not see another vehicle for half an hour. For riders who like quiet roads and forest scenery, it is an excellent route, though it demands attention and is not suited to hurry.