It has an intricate ria coastline are is noted for sea cliffs on all sides except for its western end.

Cape Kashinozaki extends from the eastern end of the island, and is surrounded by semi-submerged reefs and rocks.

Ōshima Port, which is the center of the island, has prospered from the Edo period as both a fishing port as well as shelter for boats seeking protection from inclement weather on the coastal trading route between Osaka and the eastern provinces of Japan.

Friendship Memorial Hall on the island commemorates the visit of the trade vessels Lady Washington, under Captain John Kendrick, and Grace, under William Douglas, in 1791.

[1] The Kushimoto Turkish Memorial and Museum commemorates the victims of the Ottoman frigate Ertuğrul, which sank in a typhoon off of the island in 1890 with great loss of life.