A large-scale hot spring resort hotel occupying an entire peninsula jutting into the Kumano Sea in Nachikatsuura-cho, Higashimuro-gun, Wakayama Prefecture. The greatest attraction is accessing the hotel by dedicated shuttle boat Urashima-maru (nicknamed Turtle Boat) from the tourist pier at Katsuura Port, a 5-minute ride that evokes the legend of Urashima Taro's Dragon Palace. The hotel's most famous feature is Bokikido, a massive natural cave hot spring measuring 25m wide, 50m deep, and 15m high, where Pacific Ocean waves crash dramatically against the rocks. Named during the Taisho era by Lord Tokugawa Yorisada of the Kishu domain, who described it as so pleasant that one forgets to return home. Another cave bath called Genbudo offers a different atmosphere. The hotel possesses 10 private hot spring sources on its grounds and offers 6 different baths: Bokikido, Genbudo, Taki-no-yu, Iso-no-yu, Hamayu-no-yu, and Yoho-no-yu. The water is a sulfur-containing sodium-calcium chloride spring with pH 7.3, source temperatures of approximately 51.5-52 degrees Celsius, featuring milky white sulfurous water. Since the late Heian period, nobility on Kumano pilgrimages reportedly bathed in the cave springs, and the hotel opened in 1956. With four buildings (Honkan, Nisshokan, Nagisakon, and Sanjokan), the Yoho-no-yu bath at Sanjokan offers completely free-flowing natural source water with panoramic views of the Kumano mountains and Katsuura Bay.