Masalembu Islands

Masalembu Islands (Indonesian:Kepulauan Mesalembu) lie in the Java Sea about halfway between Java and Borneo. They administratively form Masalembu District (kecamatan) of Sumenep Regency of Madura, province of East Java. Madurese is spoken on the islands. The three main islands are Masalembu Island, Masakambing Island, and Keramaian Island. The land area of the kecamatan is 40.85 square kilometers, having 20,687 people in the 2000 census, increasing to 21,705 at the 2010 count.

...
Wikipedia