Hidden in the vast interior of South Australia lies a ghost town that once bustled with life.

Today, the town of Cook is home to lonely buildings and a population of just four - all caretakers and/or maintenance workers for Pacific National.

Pacific National own the Trans-Australian Rail Line, and lease “line space” to competitors.

Most of the town's buildings are now condemned, including the impressive two-storey school.

In its heyday, it was an important part of the development of Australia’s interior.

Established in 1917, Cook was originally built as a support town for the railway, with more than 50 people helping to maintain the tracks.

The town and its station are on the longest straight section of rail track in the world, a whopping 478km long.

Freight trains a couple of kilometres long and stacked two high with 40-foot shipping containers often pass through.

The station is also used to refuel trains and as a rest stop for the drivers on their long journeys.

Just past the old train station, there are about a dozen large hose reels on the opposite side of the track.

The Indian Pacific uses these to re-fill its water tanks on the way through.

A train brings water in from Perth, sparing passengers from drinking the local bore water.