Beautiful Japanese Onsen Baths in Seaside Caves

Imagine yourself inside a cavern with the aroma of hot sulfurous water bubbling into Japanese baths and views of the Pacific Ocean. The cave opens three meters above sea level, so the roar of unrestrained marine movement enters the cave along with cooling sea breezes. Rolling waves splash onto islets, sending splatters of white sea foam toward the blue sky. 

Cave baths at Spa Bokido, Wakayama Prefecture, Japan

The contrast of natural hot water warming your entire body and the glimpses of the cold sea outside stimulate and refresh. You are soaking in an onsen facility that stands out in a country with thousands of hot springs. The photograph above shows Spa Bokido, one of the two cave bathing areas at Hotel Urashima. The hotel's other cave for bathing is named Spa Genbudo. Both are mind-blowing yet rejuvenating.

Spa Genbudo

Hotel Urashima Resort and Spa is a sprawling complex of four buildings connected by tunnels and long hallways on a peninsula along Katsuura Bay, a quiet tuna fishing town in Wakayama, Prefecture. A cute boat carries passengers from Katsura Port to the hotel for free. The atmospheric ride is only five or ten minutes. You'll pass Japan's largest tuna market and listen to the screech of black kites circling above the bay or perched on poles while seeking prey from the sea. 

Spa Hamayuu

Spa Bokido is the main attraction for onsen addicts like me. Nearly all guidebooks specializing in Japanese onsens include Bokido. Coming here was a long-time goal. Although Nachikatsuura is famous for its World Heritage Sites, including sections of Kumanokodo, a celebrated pilgrimage route, not many tourists visit it due to its remote location. Luckily, I had a work assignment that brought me nearby. When the job finished, I headed toward Hotel Urashima to fulfill an onsen lover's dream. 

Spa Isonoyu

Having to catch a train to return home at noon,  I just had time for a higaeri onsen experience, or a short day trip. My time was limited to exploring and enjoying only two bathing areas, while the hotel has at least six spa facilities. Sections of the building are in caves. The slightly aged resort hotel would have been an appropriate setting for a James Bond movie from the sixties. It reminded me of scenes from You Only Live Twice. A Shinto wedding scene that appeared in the film was filmed nearby. 

Spa Takinoyu features a waterfall pouring into the bath

The day-use fee was 1,500 yen, around 10 USD, and if I hadn't had to catch a train, I could have spent almost the entire day there. Bokido was my goal, and I was so happy while walking through a long underground corridor to the locker room, where I undressed and stepped through the doors to the cavernous bathing area, which held at least six baths. The sun entering the cave was bright at the opening; bathers at the bath closest to the sea were silhouetted by the glow, a memorable view. A walk through a tunnel brought me to another section where three more baths were located. Despite approximately thirty or forty bathers, everyone had enough space and privacy to stretch out and relax. 

One of the long hallways in the sprawling resort complex

I entered Bokido around nine in the morning, and it would close at ten for cleaning, so after relishing the beauty of this exceptional onsen, I headed at a little before ten for Spa Genbudo, which was empty. I was the only bather for about fifteen minutes. The long, narrow bath was white and sulfurous, but I discovered that the hot water pouring into a rock-lined bath at the outer lip of the cave was clear. It was either filtered or from a different source. The view was also spectacular. I spotted an arch at the tip of a tiny peninsula jutting into the sea in front of me, and I could also hear kites screeching in the sky as they circled above me. Two others, one Japanese and one French, joined me in the bath. We exchanged head nods and silently absorbed and appreciated being in the moment in one of Japan's best bathing areas.  

Spa Youhounoyu offers splendid mountain- and seascapes

Transportation to the hotel from Katsuura Pier

View from the boat heading to the onsen resort

Getting There:

The closest airport is Nanki-Shirahama Airport, and Kii-Katsuura Station is the nearest train station. Walking to Katsuura Pier takes about fifteen minutes, but taxis gather at the tiny train station when trains arrive.

More on coastal hot springs

Japan has numerous hot springs on its coast. Look below for links to some others I have written about. I would love to read your comments and suggestions regarding Japanese onsens. Please write something in the comment section of this blog. Thanks for reading. 

Onsen (Hot Spring) Addict in Japan: Multisensory Pleasures in Hot Springs on the Izura Coast

Onsen (Hot Spring) Addict in Japan: Adventures On the Way to a Bath

Onsen (Hot Spring) Addict in Japan: Seaside Japanese Hot Spring on Yakushima, Kagoshima

Onsen (Hot Spring) Addict in Japan: Hot Spring on an Island (Ioujima, Nagasaki)

Photographs of the baths were provided by the hotel. I took the other pictures. My positive review of the hotel was unpaid. I received nothing in exchange and paid my entrance fee.