The Uraga Channel (浦賀水道 Uraga-suido) is a waterway connecting Tokyo Bay to the Sagami Gulf. It is an important channel for ships headed from Tokyo, Yokohama, and Chiba to the Pacific Ocean and beyond.
At its narrowest, between Cape Kannon and Toyotsu Point, the channel is 6 km wide. During the late Edo era, it was defended against foreign ships by twelve artillery batteries on both the Boso Peninsula and Miura Peninsula. Because of this, Matthew Perry's initial expedition to Tokyo stopped at Kurihama, at the mouth of the channel.