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 (Definition of Boundaries) Order in Council, 1958. It asserts that its eastern boundary extends from the 100 fathom isobath at to while the western boundary extends from the 100 fathom isobath at to . The EEZ outer limit runs between the two distant points parallel to the coast. Brunei's EEZ claim would include waters surrounding the Spratly Islands in the South China Sea. The area claimed by Brunei however does not include any islands but includes Louisa Reef, which is currently occupied by Malaysia. Until 2009, Malaysia did not recognise Brunei's EEZ claim and stated that Brunei's maritime territories ended