Grandchester was the initial terminus of the first narrow gauge mainline railway in the world. The first track opened to traffic on 31 July 1865 from Ipswich and, although it served a very small population, Bigges Camp (as it was initially known) became the terminus for 10 months. The original railway station, including the former Station Master's residence, still exists (see Wikipedia article: "Grandchester, Queensland" for more information).
The local attractions include: the Railway Station, which has historic rail equipment on display; the Grandchester Model Steam Railway, where the locomotives are scaled down versions of actual coal burning steam engines running on over 500m of track - a great experience of living history for kids; and the nearby Bigge's Camp Park and War Memorial, which also has restrooms, picnic facilities and play equipment freely available anytime.
You do not need to enter the property to find the cache. It is a small magnetic container with log and stubby pencil only. As the location is a bit flood-prone, you would do well to attempt when the ground is dry. Do not enter floodwater for the sake of a cache. Please report if maintenace is required.