Mount Shirane (白根山, Shiranesan, often called Kusatsu-Shirane to differentiate it from other mountains called Shirane) is a series of volcanic peaks just outside the town of Kusatsu Onsen. It is a popular outdoor recreation area which offers hiking in the spring and summer, autumn colors in the fall and skiing in the winter.
Hiking is possible from mid April to early November and offers varying terrain and good views, along with a selection of trails starting at the town center or the Shirane Resthouse near the summit.
The easiest and most popular walk is from the Shirane Resthouse to Yugama Crater Lake. It takes less than ten minutes along a paved trail, and you will often see women doing it in high heels. At the top you are rewarded by views of the sulfurous, baby blue Yugama Crater Lake as well as the surrounding mountain ranges.
There are also a number of longer trails and hiking circuits that lead to the various peaks, craters, lakes and a waterfall in the area. The ropeway and chair lifts of Kusatsu Kokusai Ski Resort, which in the winter months has one of Japan's longest ski runs (8 km), can be used to bypass parts of the trails.