Edo Bay

Tokyo Bay 東京湾 Tōkyō-wan
Landsat image of Tokyo Bay
Tokyo Bay, in a narrow sense (pink) and in a broad sense (pink and blue)
Location	Honshu, Japan
Coordinates	35°25′N 139°47′E / 35.417°N 139.783°E / 35.417; 139.783
River sources	Ara River Edo River Obitsu River Yoro River
Ocean/sea sources	Pacific Ocean
Basin countries	Japan
Surface area	1,500 square kilometres (580 sq mi)
Average depth	40 metres (130 ft)
Max. depth	70 metres (230 ft)
Islands	Sarushima

Tokyo Bay (東京湾, Tōkyō-wan^?) is a bay located in the southern Kantō region of Japan, and spans the coasts of Tokyo, Kanagawa Prefecture, and Chiba Prefecture. Tokyo Bay is connected to the Pacific Ocean by the Uraga Channel. Its old name was Edo Bay (江戸湾, Edo-wan^?). The Tokyo Bay region is both the most populous and largest industrialized area in Japan.

In ancient times, Japanese knew Tokyo Bay as the uchi-umi (内海^?) or "inner sea". By the Azuchi-Momoyama period (1568 – 1600) the area had become known as Edo Bay, a reference to the city of Edo. The bay took its present name of Tokyo Bay in modern times, after the Imperial court moved to Edo and renamed that city as Tokyo in 1868.

Tokyo Bay juts prominently into the Kantō Plain. It is surrounded by the Bōsō Peninsula in Chiba Prefecture to the east and the Miura Peninsula in Kanagawa Prefecture to the west. The shore of Tokyo Bay consists of a diluvial plateau and is subject to rapid marine erosion. Sediments on the shore of the bay make for a smooth, continuous shoreline.