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
Brunei–Malaysia border Brunei–Malaysia border The border between Brunei and Malaysia consist of a 481.3 km land border and substantial lengths of maritime borders stretching from the coastline of the two countries to the edge of the continental shelf in the South China Sea. Except for its South China Sea coastline, Brunei is entirely surrounded by Malaysia's Sarawak state and the country only shares a land boundary with Malaysia. Brunei's unique shape where its territory consists of two non-contiguous portions results in its border with Malaysia being broken into two segments. Brunei's 200 nautical mile continental shelfclaim makes it a claimant of a