Welcome to Kurokawa Onsen
It's well worth an overnight in Kurokawa Onsen for a relaxing stay, but for day trippers a nyūtō tegata (onsen passport; ¥1300) allows access to three baths among the town's 24 ryokan (open 8.30am to 9pm). Buy the pass at the tourist-information desk and ask which locations are open during your visit.
Favourite baths include Yamamizuki, Kurokawa-sō and Shimmei-kan, with cave baths and riverside rotemburo (outdoor baths; Kurokawa is especially famous for its rotemburo). Many places offer konyoku (mixed bathing) alongside women-only baths.