Australia's historic railway from the southern city of Adelaide to tropical Darwin has been officially opened.
By Phil Mercer
BBC correspondent in Sydney
A freight train has begun the 3,000-kilometre journey which fulfils a century-old dream to link Australia's north and south coasts by rail.
The railway could cement Darwin's position as a gateway to Asia
There were lively celebrations in Adelaide as it departed, as onlookers lined the tracks to cheer off two locomotives painted with Aboriginal artwork pulling 100 freight cars.
The project, which cost more than A$1.2bn, was once dismissed by critics as a train line from nowhere going nowhere, but is now seen as an important new trade route.
The journey from Adelaide to Darwin will take around two days and will cross some of the country's most inhospitable terrain.
Celebrations are being planned by many remote communities along the way. The project is expected to generate a large number of jobs.
Passenger services are due to begin at the start of next month, but freight is likely to be the economic lifeblood of one of the world's last great train journeys.
CROSSING A CONTINENT
New track cost A$1.3bn ($1bn)
Construction took 30 months
Railway now runs for 3,000 kilometres (1,740 miles)
First freight train 1.8 km long
The idea of a north-south railroad was first considered by the Australian colonies in the 1870s.
It was abandoned because of the huge costs involved and the intimidating central desert, where summer temperatures can reach 50 degrees Celsius in the shade.
There are those who believe this ambitious scheme is a waste of money.
Representatives from Australia's shipping companies have insisted it will not be economically viable.