Borders have always fascinated travellers. In some ways that's strange, because they're just invisible, imaginary lines on a map.
But who hasn't felt a thrill of excitement at crossing a border on a sleeper train and having to show a passport to a guard in a peaked cap, or crossing the negligible boundary between Rome and the Vatican City and notching up another country visited?
Even internal borders can be objects of interest, and Australia's more than most. For where each of our state and territory borders meet another one at an angle, "surveyors' corners" are created, each marked by a pillar at the meeting point.
There are five of these corners, nearly all located in remote, difficult terrain. Here they are, and how to visit them.
Surveyor Generals Corner (WA/SA/NT)
The most remote of the corners, this desert location has an unexpected (and literal) twist. Though the WA border had a simple definition – the 129th east degree of longitude – it wasn't until 1922 that this was formalised as a line running north-south from two anchor obelisks. Unfortunately, it was only realised decades later that these markers were out of kilter, their surveyed lines missing each other by 127 metres.
Oops. So in 1968 two monuments were set up at the resulting right-angles where the WA border does a brief east-west zig-zag in the desert. The easternmost corner, where two states and a territory meet, was named Surveyor-Generals Corner after the three officials who attended the ceremony.
Though it's impossible to verify, it's often said that this remote point has been visited by fewer people than those who've visited the South Pole. As the corner falls within the traditional lands of the Irrunytju community, access is limited to guided tours which can be arranged by negotiation. See www.ngaanyatjarraku.wa.gov.au.
Cameron Corner (SA/QLD/NSW)
Though the eastern part of the New South Wales-Queensland border had been surveyed in the 1860s, it wasn't until 1879 that the more difficult section stretching west to the South Australian border was tackled by John Cameron of New South Wales and George Watson of Queensland.
It wasn't an easy task. They took two years to reach their final destination, impeded by the extremes of flood and drought along the way. For whatever reason, the NSW surveyor's name was the one the corner became named after.
Today it's a popular outback destination on the edge of Sturt National Park, served by the improbable Cameron Corner Store. This remote retail outpost was established by ex-Vietnam veteran Sandy Nall in 1989, when he realised how many travellers visited the border marker. It provides meals and basic cabin accommodation to travellers.
Cameron Corner can be reached by road from Tibooburra, NSW, passing the 1880s Dog Fence (built to keep dingoes out of NSW) on the way. See www.outbacknsw.com.au.
Haddon Corner (SA/QLD)
Surveying the lengthy Queensland-South Australia border was no fun for the men assigned this task in the colonial era. Taking over from a predecessor forced off the job by ill-health, German-born South Australian surveyor Augustus Poeppel and his assistant Lawrence Wells forged north in 1880 along the line from Cameron Corner to the northeast tip of South Australia.
Meeting up with Queensland surveyor Alexander Salmond, they verified the latitude by astronomical observations and marked the corner with a wooden post set above an iron bar. Haddon Corner later took its name from that of a nearby pastoral lease.
There are no facilities at this location, but it's often visited as part of the Three Corners Itinerary of the Outback Loop which links the Birdsville Track and Strzelecki Track. See www.theoutback.com.au.
Poeppel Corner (SA/NT/QLD)
After mapping Haddon Corner, Poeppel and Wells battled through the rocky arid country of the Sturt Stony Desert and the salt pans and sand dunes of the Simpson Desert. Aided by Aborigines who knew the locations of scarce waterholes, they slowly mapped a line heading west between South Australia and Queensland, to the point where it reached what is now the Northern Territory.
In December 1880 they marked this corner with a timber post, then Poeppel retired with relief to his native Adelaide. The job had ruined his health – the surveyor lost 13kg in the ordeal, and later the sight in one eye from trachoma. In a cruel twist of fate, the post he'd planted was later discovered to be incorrectly positioned, as his measuring chain had been slightly too long. Still, Poeppel could be comforted by the knowledge that this remote location was named after him.
Other than a few hardy explorers, hardly anyone visited Poeppel Corner again until the 1960s, when the adventuring Leyland Brothers popularised four-wheel-drive travel across the Simpson Desert. Since then, this remote point has become a frequent target for off-road drivers. It would be a great place to repeatedly celebrate New Year's Eve, as it's the intersection of three time zones in summer.
Poeppel Corner is located 175km west of Birdsville, accessible by 4WD along the desert track known as the QAA Line. See www.australian-4x4.com.au.
MacCabe Corner (SA/NSW/VIC)
The last of the state corners to be named, MacCabe Corner lies 100km west of Mildura, on the shore of the Murray River.
Oddly, there's another unnamed corner a short distance further west near Murtho in South Australia, dividing only South Australia and Victoria.
This anomaly arose from differences in the 1840s survey which was supposed to follow the 141st east line of longitude. Instead it fell too far west, which resulted in Victoria's border intruding 3.6km further toward South Australia than does the NSW border. The prolonged dispute over this territory wasn't resolved until it was taken to the High Court in 1911. Victoria won.
MacCabe Corner was belatedly named in 2008 after Francis MacCabe, an Irish-born surveyor who charted the rivers of the Murray-Darling basin in the mid-19th century. It can be reached by a track running off Kempe Road in Lindsay Point which, because of the quirky border, is a rare Victorian locality which lies partly west of a portion of South Australia.