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
Brunei–Malaysia border line. Malaysia's submission was jointly made with Vietnam where both countries claimed a "defined area" over which both countries currently have overlapping claims. Brunei should also have a competing claim over a portion of the "defined area". However, unlike China and the Philippines which objected to the Malaysia-Vietnam joint submission, there is no record of Brunei registering any similar objection. Brunei has not submitted its extended continental shelf claim to Commission on the Limits of the Continental Shelf. However, in its preliminary submission which it lodged with the Commission on 12 May 2009, it gave notice of its intention to