A Scenic Hot Spring Town Surrounded by the Sea and Mountains
One of the greatest attractions of Nanki-Katsuura Onsen is its spectacular coastal scenery. Numerous islands and rocky islets are scattered around Katsuura Bay, creating a landscape known as Kino Matsushima. The contrast between the deep blue sea and lush green islands creates one of the most beautiful coastal landscapes in the region.
Around Kii-Katsuura Station, visitors will find traditional shopping streets, local restaurants, and small businesses that retain the atmosphere of an old-fashioned Japanese port town. Unlike large modern resort destinations, Nanki-Katsuura has a relaxed and authentic atmosphere. Its simple streets and local character are an important part of its charm.
Nearby Katsuura Fishing Port is one of Japan’s leading ports for fresh, locally landed tuna. Visitors can enjoy exceptionally fresh seafood at restaurants and accommodations throughout the town. The combination of hot springs and outstanding seafood makes Nanki-Katsuura an especially rewarding destination for travelers.
One of Wakayama’s Richest Hot Spring Areas
Nachikatsuura Town is one of Wakayama Prefecture’s leading hot spring destinations, with approximately 177 hot spring sources. This is one of the largest concentrations of hot springs in the prefecture, making the entire town feel deeply connected to the natural bounty of its underground waters.
The history of the area’s hot springs goes back centuries. The oldest known written record is believed to be a reference to Akashima Onsen in a document dating from around 1707. The hot springs are thought to be related to groundwater and seawater heated deep underground by geological activity associated with the subduction of tectonic plates. This geological setting helps create the area’s abundant hot spring resources.
Representative Hot Spring Types
The exact mineral composition varies from one facility to another, but visitors can encounter several types of Japanese hot springs, including:
・Salt-containing hydrogen sulfide springs
・Simple sulfur springs
・Salt-containing sulfur springs
・Sulfur-containing sodium-calcium chloride springs
・Simple thermal springs
These different types of mineral-rich waters have traditionally been enjoyed for their potential benefits for conditions such as muscle and joint discomfort, lower back pain, sensitivity to cold, fatigue, and certain skin conditions. For generations, the area has attracted visitors seeking the restorative experience of bathing in natural hot spring water.
Iconic Hot Springs with Spectacular Ocean Views
Hotel Urashima’s Famous Bokido Cave Bath
One of the most famous symbols of Nanki-Katsuura Onsen is Bokido, a remarkable natural cave bath at Hotel Urashima.
The bath is located inside a huge natural sea cave carved out of the coastline by the powerful waves of the Kumano-nada Sea over thousands of years. From the opening of the cave, bathers can look out toward the vast Pacific Ocean. Listening to the sound of waves crashing against the rocks while soaking in the hot spring creates an unforgettable experience that feels closely connected to nature.
The name Bokido is traditionally said to come from an episode involving Lord Tokugawa Yorimichi, the 15th head of the Kishu-Tokugawa family. After bathing here during the Taisho period, he was reportedly so impressed by the experience that he praised it as a place so wonderful that one could forget to return home.
The cave itself is approximately 22 meters high and 1,000 square meters in area, making Bokido one of Japan’s most impressive natural cave baths.
Genbudo and the Hot Spring Experience at Hotel Urashima
Hotel Urashima offers several other hot spring facilities in addition to Bokido, including Genbudo. Guests can enjoy a variety of bathing experiences while discovering differences in scenery and mineral-rich waters.
The hotel occupies an extensive area of the peninsula, with several accommodation buildings spread throughout the property. With its many baths and facilities, the resort offers an experience that can feel like an entire hot spring village or a traditional Japanese onsen theme park.
Kishu Shio-kikin-no-Yu at Kumano Bettei Nakanoshima
Another iconic hot spring experience is Kishu Shio-kikin-no-Yu, located on the secluded island of Nakanoshima in Katsuura Bay.
The entire island is home to Kumano Bettei Nakanoshima, a distinctive Japanese inn surrounded by the sea. Its famous open-air bath sits directly beside the ocean, creating the extraordinary impression that the hot spring and the sea merge into one.
The peaceful sound of waves provides a soothing backdrop as guests relax in the mineral-rich water. The sense of exclusivity is enhanced by the fact that the inn can be reached only by its dedicated boat service. The short boat journey across the bay is itself part of the experience, adding a wonderful sense of adventure and romance to the trip.
The island has six natural hot spring sources, providing an abundant supply of hot spring water. The sulfur-containing sodium chloride spring is particularly popular with guests and is traditionally appreciated for its warming and skin-soothing qualities.
A Wide Variety of Hot Spring Inns and Resorts
Nanki-Katsuura Onsen offers a diverse selection of accommodation, ranging from large resort hotels and historic Japanese inns to facilities where visitors can enjoy hot springs without staying overnight.
Kyukamura Nanki-Katsuura
Located on elevated ground on the Ugui Peninsula, Kyukamura Nanki-Katsuura is a resort-style hotel offering expansive views of the Pacific Ocean. Its observation bath, Mezame-no-Yu, provides an impressive panorama of the sea.
The scenery is particularly beautiful around sunrise, when the first light of day spreads across the Pacific. For travelers who enjoy ocean views and peaceful mornings, this is an especially attractive place to stay.
Hotel Nagisaya
Situated beside a quiet inlet, Hotel Nagisaya is a relaxing hot spring inn known for its abundant supply of water from its own natural source.
Guests can enjoy views of the Kuroshio Current and the surrounding ocean from the open-air bath. The hot spring is also appreciated for its pleasant, skin-softening bathing experience.
Kamenoi Hotel Nachikatsuura
Overlooking Nachi Bay, Kamenoi Hotel Nachikatsuura offers a peaceful seaside setting. Its garden-style open-air bath provides views toward the mountains of Nachi and the surrounding coastline.
The hotel is also conveniently located for exploring the Kumano Kodo, Nachi Mountain, and other important cultural and natural attractions in the area.
Umi no Hotel Ichinotaki
Umi no Hotel Ichinotaki is known for its natural hot spring baths using 100% source water without reheating or dilution. All guest rooms offer ocean views, with beautiful vistas across Katsuura Bay toward Mount Nachi and Mount Myoho.
Local Public Baths Loved by the Community
Hamayu Natural Hot Spring Public Bath
Hamayu is a traditional public bath that has been enjoyed by local residents as well as visitors for many years. Rather than focusing on luxurious facilities, it offers a simple and authentic Japanese bathing experience using natural hot spring water directly from the source.
The sulfur-containing sodium-calcium chloride spring is particularly popular among hot spring enthusiasts. It is sometimes described by experienced bathers as one of the finest hot spring waters in the Nanki-Katsuura area.
For international visitors, a visit to a local public bath can also provide an opportunity to experience everyday Japanese culture. Casual encounters with local residents and the warm atmosphere of the neighborhood can become some of the most memorable moments of a trip.
A Perfect Base for Exploring the Kumano World Heritage Site
Nanki-Katsuura Onsen is an excellent base for exploring the “Sacred Sites and Pilgrimage Routes in the Kii Mountain Range”, a UNESCO World Heritage Site that reflects the deep spiritual history of the Kii Peninsula.
Major Attractions Nearby
・Kumano Nachi Taisha Grand Shrine
・Seigantoji Temple
・Hiro Shrine
・Nachi Falls
・Daimonzaka on the Kumano Kodo
・Fudarakusanji Temple
・Kino Matsushima
・Noroshi Peninsula
The Kumano region has been an important center of religious pilgrimage for centuries, and its sacred sites, ancient paths, forests, waterfalls, and temples preserve a strong sense of history and spirituality.
One of the special advantages of staying in Nanki-Katsuura is the opportunity to combine cultural exploration with relaxation. After walking along the historic Kumano Kodo or visiting the shrines and temples of Nachi, travelers can return to the hot spring town, soak in a natural onsen, and rest while listening to the sounds of the sea.
A Perfect Journey of Hot Springs and Fresh Seafood
Nachikatsuura is one of Japan’s best-known ports for freshly landed tuna. As a result, restaurants and accommodations throughout the area offer an impressive selection of fresh tuna dishes.
Visitors can enjoy classic preparations such as sashimi and sushi, as well as grilled tuna collar and dishes made with less commonly served cuts. These regional specialties provide an excellent opportunity to discover the full flavor of locally landed tuna.
The surrounding waters are also rich in other seafood, including Japanese spiny lobster, locally caught fish, and seasonal marine delicacies nurtured by the warm Kuroshio Current.
Relax in a natural hot spring, admire dramatic ocean scenery, explore the sacred mountains of Kumano, and enjoy exceptionally fresh seafood. Nanki-Katsuura brings together many of the experiences that international travelers seek when visiting Japan.
Why Visit Nanki-Katsuura Onsen?
Nanki-Katsuura Onsen is one of Wakayama Prefecture’s most distinctive hot spring destinations, combining abundant natural hot spring resources with spectacular coastal scenery, unique cave baths, oceanfront open-air baths, and easy access to the sacred sites of Kumano.
From the dramatic Bokido Cave Bath at Hotel Urashima and the secluded Kishu Shio-kikin-no-Yu at Kumano Bettei Nakanoshima to the traditional public bath Hamayu, visitors can enjoy a wide variety of bathing experiences.
The area’s appeal extends far beyond its hot springs. Fresh tuna and other seafood, the dramatic landscapes of Kino Matsushima, the historic Kumano Kodo pilgrimage routes, and the spiritual atmosphere surrounding Kumano Nachi Taisha and Nachi Falls all add depth to the journey.
Surrounded by ocean and mountains, hot springs and history, delicious local cuisine and warm hospitality, Nanki-Katsuura Onsen offers a relaxing and memorable introduction to the natural and cultural treasures of the Kii Peninsula. Whether you are seeking a peaceful retreat, a cultural adventure, or an authentic Japanese onsen experience, this remarkable seaside hot spring town is a destination worth discovering.