Guide
Sarushima is an uninhabited island located off the coast of Yokosuka City, Kanagawa Prefecture, floating in the tranquil waters of Tokyo Bay. Currently maintained as "Sarushima Park" by the city, it serves as a unique destination where history and nature coexist. The island is a designated national historic site, preserving the remains of artillery batteries and fortresses built during the late Edo to Meiji periods. Beyond its historical significance, it is a popular leisure spot for enjoying nature through walking tours and barbecues.
The island has a deep historical connection to the region. Archaeological finds, including pottery and remains from the Jomon and Yayoi periods, indicate human presence dating back thousands of years. Historically, the island was also part of the Kasuga Shrine grounds. In 1847, during the late Edo period, the Tokugawa Shogunate constructed the first artillery battery here. During the Meiji era, the island came under military control and developed into a significant fortress guarding Tokyo Bay. The brick-built ruins remaining on the island are precious historical artifacts that showcase the engineering techniques of that era. After World War II, the island was briefly under U.S. administration before being returned to Japan, and it is now preserved as a vital cultural heritage site.
The most striking feature is the fortress ruins. The brick structures, carved into the rocky cliffs, showcase a rare "Flemish bond" masonry technique that is uncommon in Japan. Many visitors are drawn to the island's mysterious atmosphere, which many say evokes the world of the famous anime film "Castle in the Sky" (Laputa). The well-maintained walking paths allow you to enjoy breathtaking views of the calm Tokyo Bay waters against the backdrop of historical ruins.
Access to Sarushima is via a boat service from Mikasa Terminal. Please note that the boat schedule changes depending on the season: there is a "Summer Schedule" from March to October and a "Winter Schedule" from November to the end of February. The boat ride takes approximately 10 minutes one way. For the best experience, visiting on a clear morning is highly recommended, as the contrast between the historical ruins and the sparkling blue sea is truly spectacular.
There are various ways to enjoy the island's natural environment. You can enjoy a relaxing stroll along the paths or host a barbecue on the sandy beach (equipment rental is available). For those seeking a deeper understanding of the island, specialized "Exploration Tours" are offered, including 30-minute and 60-minute programs. These guided tours provide a unique perspective on the island's history and geology that a standard walk might not offer.
To reach Sarushima, take a boat from Mikasa Terminal, which is about a 15-minute walk from the Keikyu Line "Yokosuka-Chuo Station." The area around Mikasa Terminal is steeped in Yokosuka's maritime history, making it easy to plan a full day of sightseeing around the boat departure times. The island is strictly managed to balance tourism with environmental conservation.
Because the island features unpaved paths and rocky terrain, we strongly recommend wearing comfortable walking shoes or sneakers. Please prepare for your boat trip and outdoor activities in advance. Regarding payments, please check in advance whether the boat operator or facilities accept cash or credit cards. While some English signage and information are available, please follow local rules and etiquette. To protect the natural environment, please ensure you take all trash home with you and respect the local ecosystem.