Lake Nakaumi is a brackish lake located in Shimane Prefecture, Japan. It is the second-largest lake in the country, covering an area of approximately 80 square kilometers. The lake is known for its unique ecosystem, which supports various species of fish and birds, making it a popular spot for birdwatching and fishing. The lake is connected to the Sea of Japan through a narrow channel, allowing for the exchange of saltwater and freshwater. This connection contributes to the lake's diverse habitats. Additionally, Lake Nakaumi is surrounded by scenic landscapes, including mountains and wetlands, attracting visitors for recreational activities and nature exploration.