noun
Seto Inland Sea; Inland Sea
Proper noun referring to the body of water separating Honshu, Shikoku, and Kyushu.
瀬戸内海は多島美で知られている。
The Seto Inland Sea is known for its scenic archipelago.
Compound of 瀬戸 (seto, 'strait') + 内海 (naikai, 'inland sea').