Distance: 7.7 km
Elevation change: 270 metres
Highest point: 634 metres
Start: Otsuki Station (JR Chuo Main Line)
Finish: Otsuki Station (JR Chuo Main Line)
A Mighty View from a Towering Cliff Face
Mt. Iwadono has a few things going for it: historical roots, excellent access right next to Otsuki Station, and a prodigious view of Mt. Fuji in clear weather. It is also recognised as one of the 100 famous mountains in Yamanashi. Traveling by train through Otsuki Station, it’s hard to miss its impressive rock face. From the station to the summit, it takes a little over an hour, making it suitable for beginners as well as families.
Access-wise, you’re looking at 1 hour, 45 minutes (1,340 yen) from Shinjuku Station to Otsuki Station 大月駅 on the JR Chuo Main Line. After exiting the ticket gate, turn left and walk along the street lined with shops. Cross the train line and turn left at the Tokyo Electric Power Company (TEPCO) building, which takes you across a bridge and onto National Route 139. The old Iwadonosan parking area is on your left. Typhoon Hagibis in 2019 damaged the previous trail via the Kagami-iwa 鏡岩. Walking up the steps of the former trail, however, affords a nice view of Fujisan. The new Hatakura trailhead 畑倉登山口 is a further 20-minute walk from here just past the ‘Driving school’ bus stop.
A short distance from the trailhead finds a junction. Turn left for the Oni-no-iwaya 鬼の岩屋, a limestone cave where the ogre of Mt. Iwadono lived. It is usually hidden behind the waterfall, but in winter, when the waterfall freezes, the entrance to the cave can be fully seen. From the cave, it’s about a 30-minute hike to the summit. Halfway up the trail, it steepens, and the gravel surface underfoot makes it hard to get traction at times. At an altitude of 634 metres Iwadonosan 岩殿山 is the same height as the Tokyo Skytree, and the unobstructed view of Mt. Fuji is spectacular. During the Warring States period of 1467–1568 CE, the Iwadono Castle 岩殿城 was built here and guarded the border regions of Kai (present-day Yamanashi), Sagami, and Musashi provinces. Prior to that, it was the site of a famous thirteenth-century Buddhist temple complex known as the Iwadono Gongen 岩殿権現.
An equally impressive panorama of Fujisan can also be had from an observation spot just down from the summit, past an area known as Yosuike 用水池. To the north-west, you can make out Shirayanomaru, a picturesque open grassland reminiscent of a high alpine pasture. After soaking up the views, it’s simply a matter of retracing your steps all the way back to Otsuki Station. For those looking for something more, the hike can be extended to the nearby Chigootoshi 稚児落とし and Mt. Tenjin 天神山. Be warned, though: to climb these peaks, you will need to negotiate some fixed chains. Look out for a future installment when I challenge the full-loop course in the coming months.