The Greta Main Colliery was established around the turn of the century and at its peak employed 165 men and 100 horses. It was named after the very high quality coal seam that stretches from Greta towards Wollombi and was operated on land that was originally a sheep station called Wyalla. The coal was extracted via a tunnel shaft which ran into a labyrinth of workings on the opposite side of Wollombi Road.

The main features of the Pay Office are the pay window, the brick entrance and the safe (which was large enough to convert to a kitchen). Also of interest is the Manager's residence, which is adjacent and occupied by the owner/operaters Colin & Lorraine. Other features of the property (relevant to the colliery) are the arches which provided support for the timber hoppers used to load rail trucks, the foundations for the washing plant and the numerous dams that provided water for the washing process. The colliery ceased operating in 1973 and the majority of the 84 acres was returned to native bushland.