Kusatsu is a quintessential onsen town located in Gunma Prefecture, Japan. It is widely regarded as one of the best onsen towns in the country and is very popular among Japanese visitors, though not as well known among international tourists. The town is literally built around a hot water field called the Yubatake, which cools the abundant hot spring water before it is delivered to the ryokans around town.
The town is also dotted with public foot baths that everyone can enjoy, which I think is unique to Kusatsu.
We spent three fantastic and relaxing days in the town, staying at an all-inclusive ryokan where we had our own private bath on the balcony with fresh hot water on demand, as well as access to three themed private onsens and two public onsens within the resort.