 Many of the islands and their features were subsequently named by members of the Japanese Antarctic Research Expedition (JARE); unless otherwise noted, features noted in this article were named by JARE.The Flatvaer Islands are separated from Lützow-Holm Bay by Ongul Sound, which is wide and named in association with Ongul Island.On its east margin, opposite East Ongul Island, sits a small cluster of rocks called the Mukai Rocks.