Route Overview: Iiyama to Kusatsu via Mt. Shirane

This route is one of the most challenging climbs in the region, starting in the northern Nagano area and ending in the well-known hot spring town of Kusatsu. Along the way, riders pass wild monkeys, ski resorts, and Japan's highest national highway, with a rewarding descent into town for a well-earned soak.

The route begins with a steady climb toward the Snow Monkey Park. Though touristy, it's a rare opportunity to see wild monkeys soaking in hot springs - worth a brief stop if timed well. Nearby, the traditional onsen town of Shibu Onsen offers atmospheric streets for a quick photo break before the steep ascent begins.

The main climb gains over 1,550 m in elevation over just 24 km, culminating at 2,172 m above sea level. This section - only recently reopened after winter - takes riders past ski resorts and deep snow walls near Mt. Shirane. Although the active volcano's crater is technically accessible, warnings about fumes mean most riders skip the detour.

From the visitor center, the road descends roughly 900 m over 15 km into Kusatsu Onsen, one of Japan's best-known hot spring towns. While the village is touristy, it's still worth visiting for its iconic yubatake - a massive wooden structure that cools the spring water as it cascades into the public bathhouses.

Many inns here offer yukata robes and bath kits for wandering between hot springs. Dinner options range from traditional full-course meals to casual yakitori shops near the main square.