an inlet of the Pacific Ocean, on southeastern Honshu Island, in Japan. The bay is separated from the open ocean by the Boso Peninsula and is connected to the Sagami Sea by the narrow Uraga Strait, which is only 9 km across. Tokyo Bay is about 50 km long, up to 37 km wide, and 15–30 m deep. The shores are low-lying. It receives the Ara River. The cities and ports of Tokyo, Kawasaki, Yokohama (or Keihin), Yokosuka, and Chiba are located on the western shore of Tokyo Bay.