Invincible Colliery is situated in the Western Coal Fields of New South Wales and is located near the township of Cullen Bullen, some 160 Kilometres west of Sydney.

Invincible Colliery holding comprises an area of approximately 2,500 ha. and was originally worked at the beginning of the last century.

The mine is well equipped with coal handling and preparation equipment originally designed to service the production from the previously utilised 1.5 million tonne per annum longwall mining system. This longwall system was shut down and removed from the mine in 1988 due to a down turn in the local coal mining industry.

The mine was acquired by Coalpac Pty Ltd (Coalpac) in 1989 and operated as a bord and pillar operation and more recently as an open cut operation. Production from Invincible Colliery is currently drawn from the Open Cut via conventional operations using a combination of trucks, excavators and loaders to recover coal from the Lithgow, Lidsdale and Irondale Seams. The operation  produced 1,000,000 tonnes per annum to a mixture of power station supply and domestic thermal coal producers.

The mine was acquired by Castlereagh Coal in 2015 and is currently being maintained under Care and Maintenance