Surrounded by steep cliffs and rocky islets, it is a haven for sea birds. The warm Tsushima Current brings abundant marine life to the surrounding waters and species normally found much further south abound.
It was known as Totomoshiri to its original Ainu inhabitants. It came under the daimyo of Matsumae in the eighteenth century and got its current European name from a visit of the French navigator La Perouse who named it Moneron after one of his engineers. Latterly, the Japanese named it Kaibato but it reverted to its European name after Japan's defeat in World War II and its occupation by Russia.
At lat. 46 16N, long. 141 15E, it has an area of about 30 km² and a highest point of 429m. It has no permanent population.