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
Indonesia–Malaysia border Island. A stretch of the Indonesia–Malaysia border will run in between. This will effectively establish three Indonesia-Malaysia-Singapore tripoints in the area. The determination of boundaries to fill the various gaps and defining the various tripoints would require Indonesia-Malaysia-Singapore trilateral negotiations. Again, the only a continental shelf boundary has been agreed to in this segment of the maritime border between the two countries. The boundary begins at Point 21 with coordinates 109° 38'.8E 02° 05'.0N (109° 38' 48"E 02° 05'N) off Tanjung Datu at the western extremity of the Malaysia state of Sarawak. Incidentally, the Indonesian baseline at Tanjung Datu is