A signature open-air cave bath and one of Japan’s most famous attractions, named after Kishu domain lord Tokugawa Yorimichi, who praised it as "so wonderful you would forget to go home." Within a natural cave facing the rough waves of the Pacific Ocean, superb self-owned hot spring water with a milky-white or emerald-green hue flows in constantly as 100% free-flowing natural hot spring water, creating a breathtaking bathing experience.

A cave bath formed by wave erosion, filled with the mysterious beauty of untouched nature. Fresh hot spring water that springs directly from the facility’s own source flows straight into the bath as 100% free-flowing natural hot spring water. Soaking in the rich, sulfur-scented water while listening to the sound of the waves echo through the cave is a truly transcendent experience.

A collection of distinctive large public baths equipped in each guest room building, all supplied with 100% free-flowing natural hot spring water. Nachikatsuura Onsen is a premium hot spring known for its mildly alkaline water that helps cleanse and brighten the skin, as well as its excellent warming effect thanks to its abundant salt content. From Yaho-no-Yu, exclusive to guests staying in the Yamagamikan building, you can enjoy a panoramic view of Katsuura town and the Pacific Ocean below.