Mountain: Iodake (硫黄岳 Yatsugatake massif)
Mapsheet: 32 [Yama-to-kougen-chizu (山と高原地図) series]
[Note: This topo is from the Japanese "Challenge! Alpine Climbing" guidebook (ISBN4-8083-0793-6). Buy this book if you can, it's the bible of Japanese alpine climbing outside of the N Alps.]
It is generally regarded as a training area, good for beginners as well as more experienced ice climbers, so it can get pretty crowded in there when the weather is good. To get there, head up into the forest from outside the entrance to the Akadake-kōsen hut, and follow the trail for about 15-20 minutes, past the entrances to the Daidoushin and Uradoushin gullies. They are all signposted, so you shouldn't get lost.
The terrain in Jogosawa is absolutely stunning, including a lovely canyon flanked by steep rock walls, with a fun and gentle icefall (F3) running down it.
Above the upper falls (Niagara, Ōtaki etc.) steep slopes lead up to the summit ridge of Iodake.
Here are some of the highlights of this lovely sawa:
Entrance to Jogosawa:
F3 in the canyon:
Coming up to F3:
Icefall above the canyon:
Looking back at the canyon:
View to Amidadake:
Jogosawa Ōtaki (大滝):