The Bôsô Hantô is located in Japan's Chiba prefecture, just east of Tokyo. It separates Tokyo Bay, on the west, from the Pacific Ocean, on the east. The cities of Kisarazu and Tateyama are located on the peninsula. Most of the peninsula is hilly, with some points as high as 400 m above sea level: the river valleys are mostly used for growing rice. The peninsula is connected to the rest of Japan by the Uchibo and Sotobo railway lines, and by the Tokyo Bay Aqualine expressway. Historically, the central part of the peninsula was known as Kazusa, and the southern tip was known as Awa.