Indonesia–Malaysia border Indonesia–Malaysia border The border between the Southeast Asian countries of Indonesia and Malaysia consist of both a land border separating the two countries' territories on the island of Borneo as well as maritime boundaries along the length of the Straits of Malacca, in the South China Sea and in the Celebes Sea. The land boundary has a length of 2,019.5 km and stretches from Tanjung Datu at the northwestern corner of Borneo, through the highlands of the Borneo hinterland, to the Gulf of Sebatik and the Celebes Sea in the eastern side of the island. The boundary separates the Indonesian
Peninsular Malaysia agreement with Federation of Malaya in forming the Federation of Malaysia. Peninsular Malaysia Peninsular Malaysia also known as Malaya or West Malaysia, is the part of Malaysia which lies on the Malay Peninsula and surrounding islands. Its area is , which is nearly 40% of the total area of the country - - or slightly smaller than England and Java island. It shares a land border with Thailand in the north. To the south is the island of Singapore. Across the Strait of Malacca to the west lies the Sumatra Island (Indonesia) and across the South China Sea to the