in Philippines v. China (2016), the Court ruled in favour of the Philippines and rejected China's claims. Geography Indonesia is the largest country in Southeast Asia and is also the largest archipelago in the world by size (according to the CIA World Factbook). Geologically, the Indonesian Archipelago is one of the most volcanically active regions in the world. Geological uplifts in the region have also produced some impressive mountains, culminating in Puncak Jaya in Papua, Indonesia at , on the island of New Guinea; it is the only place where ice glaciers can be found in Southeast Asia. The highest mountain in Southeast Asia is Hkakabo Razi at and can be found in northern Burma sharing the same range of its parent peak, Mount Everest. The South China Sea is the major body of water within Southeast Asia. The Philippines, Vietnam, Malaysia, Brunei, Indonesia, and Singapore, have integral rivers that flow into the South China Sea. Mayon Volcano, despite being dangerously active, holds the record of the world's most perfect cone which is built from past and continuous eruption. Boundaries Geographically, Southeast Asia is bounded to the southeast by the Australian continent, the boundary between these two regions is most often considered to run through Wallacea. Geopolitically, the boundary lies between Papua New Guinea and the Indonesian region of Western New Guinea (Papua and West Papua). Both countries share the island of New Guinea. Islands to the east of the Philippines make up the region of Micronesia. These islands are not biogeographically, geologically or historically linked to mainland Asia, and are considered part of Oceania by the United Nations, The World Factbook and other organisations. The Oceania region is politically represented through the Pacific Islands Forum, a governing body which, up until 2022, included Australia, New Zealand and all independent territories in Melanesia, Micronesia and Polynesia. Several countries of Maritime Southeast Asia, such as Indonesia and the Philippines, are dialogue partners of the Pacific Islands Forum, but none have full membership. Maritime Southeast Asia was often grouped with Australia and Oceania in the mid to late 1800s, rather than with mainland Asia. The term Oceania came into usage at the beginning of the 1800s, and the earlier definitions predated the advent of concepts such as Wallacea. The non-continental Australian external territories of Christmas Island and Cocos (Keeling) Islands are sometimes considered part of Maritime Southeast Asia, as they lie in