There is no Australian state which shares a border with all other states. No state except for Victoria shares a land border with Tasmania. South Australia shares a border with all mainland states and the Northern Territory.
South Australia
Because, Its in the Northern territory Border
The top of Queensland is the most northern part of Australia. This is known as Cape York Peninsula. The most northern single state or territory is the Northern Territory. , and it does not extend as far south on its southern border as Queensland.
The State of South Australia completely adjoins the southern border of the Northern Territory.
The Australian Alps are the highest mountain range on mainland Australia. Part of the Great Dividing Range which extends from the northern tip of Australia right down to Victoria, the Australian Alps are positioned roughly in Australia's southeast, on the border of Victoria and New South Wales.
The question does not make sense. All of the states of Australia share a border with another state. Even Tasmania, the island state, shares an actual land border as well as a water border with another state.
the unicorn territory, and the dinosaur river
It is Alaska.
Alaska
Poeppel Corner is where the borders of the Northern Territory, South Australia and Queenslandmeet.
The mainland part of the Australian Capital Territory does not have a coastline. It is entirely encompassed by the state of New South Wales. The length of its border is 306 km. However, Jervis Bay is the naval port of the ACT, located several hundred years away, on the southern NSW coast. The mainland length of the Jervis Bay territory of the ACT is 54 km, and the island length is 3 km.
Northern Ireland - it shares a border with Eire - but is a separate island from the mainland.