Sandan　三段山　1748m

Sandan has a lot to recommend it.  There's a great new onsen at the base (Fukeage onsen) which is cheap (500Y) and quite large.  There's also a campground.  In the summer it's a short hike to the top and back, leaving you plenty of time to relax in the onsen.  There's also a free, outdoor onsen fairly near Fukeage onsen.

The winter is also a great time to climb Sandan.  Unlike other mountains in the Taisetsu range, this one is considered relatively safe in winter.  On clear days you get a magnificent view of Tokachidake and other mountains around Sandan. 

Fukeage onsen has a limited number of snowshoes that they rent out for 500 Yen for the day. 

Access: Get to Kamifurano and turn east towards the mountains.  Kamifurano has an English tourist page (from where this map was copied).  Check it out - there's a lot more to do in and around Kamifurano. 

Once you get to the onsen you, the hike up to Sandan is pretty straightforward.  Figuratively and literally.  Go straight and up.

The map on the left (also from the Kamifurano tourist page) shows the trail going up to Sandan.  Note, that you can also go up via Tokachidake onsen.  This is considered less safe in winter than the Fukeage onsen route due to avalanches.  On another safety note, you can see a dotted line leading from Sandan to the ridge connecting with Tokachidake.  This is quite difficult in summer and possibly dangerous.  In winter it would be absolute madness. 

The picture on the left shows an intrepid climber who is just a few minutes from the top.  He managed to make it party due to skill, endurance, fortitude and stamina, but mostly because he had a flask of whiskey in his pocket and he promised himself he wasn't going to have a drink 'til he got to the top.