Uraga Channel - Geography

Geography

The Uraga channel is at the southern end of Tokyo Bay (formerly known as Edo Bay, prior to 1868).

Tokyo Bay is surrounded by the Bōsō Peninsula (Chiba Prefecture) to the east and the Miura Peninsula (Kanagawa Prefecture) to the west. In a narrow sense, Tokyo Bay is the area north of the straight line formed by the Cape Kannon (観音崎, Kannon-zaki?) on the Miura Peninsula on one end and Cape Futtsu (富津岬, Futtsu-misaki?) on the Boso Peninsula on the other end. This area covers about 922 km². Tokyo Bay, in a broader sense, would be understood to include the Uraga Channel as well (its southwestern demarcation being the straight line between the Tsurugisaki Lighthouse and Sunosaki Lighthouse); and the total area of the bay would then be 1320 km².

The city of Uraga is located at the northern end of the channel on the Miura Peninsula. Due to its strategic location at the entrance of Edo Bay, Uraga has often been the first point of contact between visiting foreign ships and Japan.

At its narrowest, between Cape Kannon and Futtsu Point, the channel is 6 km wide. During the late Edo period, it was defended against foreign ships by twelve artillery batteries on both the Bōsō Peninsula and Miura Peninsula.