O-yu is one of Nozawa's most impressive public hot springs, sitting right in the center of the village on that main onsen street. It's basically Nozawa's crown jewel of hot springs - this beautiful traditional building with that classic steep roof that looks exactly like what you imagine a mountain onsen should be.

What makes it special (besides being super convenient to most hotels) is how it's one of the largest and hottest of Nozawa's public baths. The building itself is gorgeous - that traditional architecture with the steam rising up makes for perfect winter photos.

Pro tip: Like all public onsen in Nozawa, it's free to use (though donations are appreciated), but be ready - the water here is seriously hot! It's one of those authentic Japanese experiences where you're soaking alongside locals who've been using these same baths for generations.