The Border Loop
This cache is not located in the Border Ranges National Park, but just outside it's perimeter.
Border loop, also known as Spiral loop, was the first standard gauge railway linking two capital cities in Australia. Construction of the line between Sydney and Brisbane began after World War I, when there was a need to create employment as the country was in the midst of the Great Depression. 1500 people were employed on the project.
The loop serves to get trains over the border and give elevation to the trains to pass over the mountainous range. By circling the hill at the end of the valley, and cutting through a series of tunnels, the train track gains 20m of height in a gradient of 1.5%
This cache is near the lookout, where if you are lucky you'll see a train take the loop, and snake it's way around the hill, while disappearing and reappearing from the tunnel. It's a small container, but only really has a room for the log and pencil and maybe a small trackable or coin.