Sarushima is the only deserted island in the Tokyo Bay area and is also the biggest natural island. Here you can enjoy many activities such as barbecue, fishing, strolling around major historical ruins, and gathering shellfish. Every year from mid July to end August, the beach is open for swimming. It takes approximately 30 minutes to get there by boat from the Keio Line Yokosuka Chuo Station. (The boats to Sarushima have different capacities, ranging from 80 people to 200 people maximum depending on the season.) This easily accessible sightseeing spot is designated as a National Historic Site.