A ceremony is being held to mark the completion of the historic Darwin to Alice Springs railway in Australia.
By Phil Mercer
BBC correspondent in Sydney
It has taken two and a half years to finish, at a cost of $800m.
The new railway has been built across some of the world's most inhospitable territory.
It will provide what has been described as a "land bridge" from southern Australia to the port of Darwin and beyond into Asia.
A railway across the unforgiving "Red Centre" has been a dream for Australians for generations.
In the early 1980s, the former Prime Minister Malcolm Fraser announced it would be built within five years.
A number of factors conspired to derail such optimism, including the cost and the sheer hostility of the terrain.
In the summer, temperatures reach 50C in the shade. On top of that, there is a three-month monsoon season.
For most of its length, Australia's newest railway line runs along a small embankment through the Tanami Desert.
It stretches for more than 1,400 km (870 miles) over 90 bridges.
Its main purpose will be transporting freight between Adelaide in the south and tropical Darwin in the north. The journey will take almost two days.
The famous "Ghan" passenger train will also travel on the new route.
Services are scheduled to start in the New Year.
There are high hopes the trans-continental link will make Australia's trade with its Asian neighbours quicker and more profitable.
The Alice Springs to Darwin scheme is jointly managed by the South Australian and Northern Territory governments. The design, construction and day-to-day running of the railway are the responsibility of a private consortium.