The land border of the state of Western Australia (WA) bisects mainland Australia, nominally along 129th meridian east longitude (129° East). That land border divides WA from the Northern Territory (NT) and South Australia (SA). However, for various reasons, the actual border (as surveyed and marked or otherwise indicated on the ground) deviates from 129° East, and is not a single straight line. The Western Australian town closest to the border is Kununurra, which is about west of the border with the NT. The settlement outside WA that is closest to the border is Border Village, SA, which adjoins the border; the centre of Border Village is about from the border, on the Eyre Highway. Border delineation In some cases, the physical signage and structures that mark the actual border deviate from the 129th meridian. The Northern Territory border with Western Australia and the South Australian border with Western Australia are displaced east–west by approximately , as a result of errors caused by the technical limits of surveying technology in the 1920s, when the current border was surveyed. Consequently, since the 1920s, the border has included an approximate east–west "dog-leg", which runs along the 26th parallel south latitude (26° south), immediately west of Surveyor Generals Cornerthe point at which WA officially meets both the NT and SA. In June 1968, monuments were erected to mark both ends of this east–west line. History 1788–1825 In 1788 Governor Phillip claimed the continent of Australia only as far west as the 135th meridian east (135° east) in accordance with his commission. (26 January 1788 – MAP) It has been suggested that the 1788 claim by the British of 135° east was in reference to Spain's claims under the Treaty of Tordesillas. Spain was seen as no longer having an interest in the area. On the other hand, the other signatories to the treaty, the Portuguese still had a presence in Macau and East Timor. Adoption of 135° east as a boundary would minimise provocation of the Portuguese. By 1825, however, Britain was powerful enough and found it convenient to adopt the original line of the Portuguese under the treaty, 129° east. 1825–29 The line of 129° east first became a border in Australia as the western border of New South Wales (NSW) in 1825 (16 July 1825 – MAP). On 16 July 1825, the western boundary of New South Wales was relocated at