Queensland's historic line from Murphy's Creek to Toowoomba, completed in 1867, was the world's first main line narrow-gauge railway to scale a mountain range.
From 250m above sea level, it rises to 441m at Toowoomba in 30km; the ruling grade is 1 in 50.
Until the 1990s, it was a major artery. It was sold to a private operator in 2009.
Traffic now consists almost exclusively of coal.
Approximate run time: 35 minutes.