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 their boundary issues and demarcate their common border according to the five historical agreements, of which the two directly concern Limbang, namely the 1920 agreement establishing the Pandaruan River as the Brunei-Sarawak border to the east of Limbang, and the 1933 agreement establishing the Brunei-Sarawak border to the west of Limbang. The two countries also agreed to use the watershed principle to fill in the gaps. This essentially reaffirms the current de facto boundary without major deviation. This led Malaysia to declare that the Limbang Question has been settled with Malaysia having unequivocal ownership over Limbang. Brunei however immediately denied