The Dumoulin Islands belong to the western foothills of Louisiade archipelago.

The four islands rise from an undersea shelf of about 6 km (3.7 mi) in length up to 110 m (360 ft) above sea level.

They are hilly, wooded with steep slopes and cliffs and dense.

Baiiri, the largest island, is located at the western end of the group, the second largest island Ana Karu Karua at the eastern end.

The first recorded sighting by Europeans of Dumoulin Islands was by the Spanish expedition of Luís Vaez de Torres on 20 July 1606.