Panduan
Okinoshima Beach is a tombolo (a land-connected island) located in Tateyama City, Chiba Prefecture. Originally an island separated from the mainland, the landscape changed due to land uplift during the 1923 Great Kanto Earthquake, creating the current sandbar connection. The island's circumference is slightly less than 1 km, and it is connected to the mainland by a sandy path of about 200 meters, making it easily accessible on foot. The water quality and clarity are exceptional, having been certified with the highest 'AA Rank' by the Ministry of the Environment's water quality survey. When the sun shines, the sea sparkles in a brilliant marine blue. As part of the Minamiboso Quasi-National Park, the area maintains a rich and diverse marine ecosystem.
The topography of this area has a fascinating history. While it was once an offshore island, the geological shifts from the Great Kanto Earthquake caused changes in currents and sand accumulation, forming the current land bridge. The island is also home to the Okinoshima Uga Daimyojin Shrine, which is said to have been established in 1096. Additionally, the island holds historical traces from its time as part of the Tokyo Bay fortification system, including man-made underground bunkers. It is a place where natural-driven geological changes and human history intersect.
The greatest charm of Okinoshima is its transparent sea and diverse ecosystem. The surrounding waters are known as a northern limit for certain coral species, and visitors can observe coral even in shallow areas through snorkeling or free-diving. The island's flora is also noteworthy, with tropical-looking plants like Hibiscus tiliaceus and Pandanus-like vegetation creating a lush environment. At the entrance to the island, a natural tunnel formed by overhanging trees offers a beautiful, scenic way to begin your exploration.
The beach is primarily open during the summer season (late July to late August). During this period, several 'Umi-no-ie' (beach huts) are set up on the sandy area, providing more comfort for visitors. The best time to visit is during sunny daytime hours when the sunlight turns the sea into a vibrant marine blue, making underwater scenery breathtaking. Additionally, when the tide is low, the rocky tide pools become exposed, making it an ideal time for observing small marine creatures.
Okinoshima offers a variety of activities within nature. Beyond swimming, you can enjoy exploring the rocky inlets and observing marine life among the rocks during low tide. Snorkeling and free-diving in the coral-rich waters are highly popular. On the sheltered side of the island, the sandy beach often brings in beautiful seashells and sea glass, perfect for beachcombing. You can also enjoy walking along the island's trails to explore the rich plant life and natural landscape.
The area around Okinoshima is part of the scenic Minamiboso Quasi-National Park. Please note that parking is limited to roadside spaces rather than a formal parking lot. For convenience, there is a Seven-Eleven convenience store on the mainland side before you cross to the island, which is a great place to purchase drinks and snacks before your visit. The area can be easily integrated into a larger sightseeing route including Tateyama Port.
As this is an uninhabited island, there are no vending machines or restaurants. It is essential to bring your own food and drinks. We recommend wearing swimwear, comfortable walking shoes for island exploration, and a hat for sun protection. To preserve the environment, please ensure that any stones turned over during tide pool exploration are returned to their original positions. While lifeguards are present during the official beach season, swimming outside these times or in certain areas is at your own risk.