East Malaysia is 50% bigger than Peninsular Malaysia at , comparable with South Dakota or Great Britain. East Malaysia contains the five highest mountains in Malaysia, the highest being Mount Kinabalu at 4095 m, which is also the highest mountain in Borneo and the 10th highest mountain peak in Southeast Asia. It also contains the two longest rivers in Malaysia – Rajang River and Kinabatangan River. Banggi Island in Sabah and Bruit Island in Sarawak are the two largest islands that are located entirely within Malaysia. The largest island is Borneo, which is shared with Indonesia and Brunei. The second largest island
Indonesia–Malaysia border by an International Court of Justice ruling. Malaysia's 1979 map No maritime border agreement covers the continuation of the border from the southern terminus of the continental shelf boundary to the meeting point of the territorial water of Indonesia, Malaysia and Singapore which should lie in the area. Malaysia and Singapore have also yet to determine their mutual border from the eastern terminus of the Malaysia-Singapore border which was as determined in the 1995 Malaysia-Singapore border agreement to the tripoint. Malaysia's 1979 continental shelf and territorial sea map unilaterally connects the southern terminus of the Indonesia-Malaysia continental shelf boundary with