By plane
South Australia's main air gateway is Adelaide Airport, IATA: ADL (http://www.aal.com.au/), which has most domestic and all international flights direct into the state. International flights direct into Adelaide include those from Denpasar in Indonesia, Singapore, Kuala Lumpur in Malaysia and Auckland in New Zealand. There are regular domestic flights into Adelaide from all Australian capital cities and some interstate regional centres such as Mildura in Victoria, Broken Hill, Kalgoorlie-Boulder airport and Broome in Western Australia, Alice Springs and Darwin in the Northern Territory.
Mount Gambier Airport, IATA: MGB in the far south-east of the state has services from Melbourne in Victoria, flown by Regional Express REX. (http://www.rex.com.au/)
By train
Adelaide is a hub for Great Southern Railways (http://www.gsr.com.au) which runs long-distance train services. Note that GSR's services are aimed at tourists and are are a trip in themselves rather than something to use to get to places. All GSR's services pass through or depart from Adelaide. Train services include:
The Indian Pacific, between Perth & Sydney, normally twice a week in each direction
The Ghan, between Darwin and Adelaide, twice a week in each direction
The Overland, between Melbourne and Adelaide, three times a week in each direction
From Adelaide, Brisbane can be accessed by the Indian Pacific to Sydney and changing for the CountryLink XPT service to Brisbane.
V/Line have a daily coach service from Adelaide connecting to the Countrylink XPT Service in Albury to Sydney.
By ship
Adelaide's Overseas Passenger Terminal is at Outer Harbor on the LeFevre Peninsula in the north of Adelaide. Visiting cruise ships often dock here.
By car
There are main road connections through to the other states and territories. The main routes are:
From New South Wales:
via the Barrier Highway A32, west of Broken Hill
From Victoria:
via the Sturt Highway A20, east of Yambavia the Mallee Highway B12, east of Pinnaroovia the Dukes Highway A8, east of Bordertownvia the Princes Highway A1, east of Mount Gambier coastal road
From the Northern Territory:
via the Stuart Highway A87
From Western Australia:
via the Eyre Highway A1
Note that South Australia has a very large land area with most settlements in the south-east of the state. Driving to the Northern Territory and Western Australia are very long drives. From Adelaide to Perth is 2,700 km and will take at least 2 days, probably 3. It is the sort of trip that even most locals only do once or twice in their lifetime. Driving from Adelaide to Darwin is just over 3,000 km and travels through some very remote parts of Australia. A minimum of 4 days is recommended. Sydney to Adelaide takes about 18 hours to drive allow 2-3 days, and Adelaide to Melbourne is around 10-11 hours depending on the route taken. Allow 2 days to admire the towns on the way.
By bus
Interstate bus services are provided by Greyhound Australia (http://www.greyhound.com.au/), Firefly (https://www.fireflyexpres...) and VLine (http://www.vline.com.au/), these services also serve multiple intrastate destinations on route.Transfers are available to Adelaide airport and Keswick interstate rail terminal from the Adelaide Central Bus Station. (http://www.cityofadelaide...)