Sunk in 1875 by Moses Rowlands and reached the main coal seams in 1879.

Naval Steam Colliery, consisted of a unit of four collieries they were; Pandy colliery or Naval No. 1, Tonypandy, Sunk by Naval Colliery Co. in 1879: Ely colliery or Naval No. 2, Penygraig, Sunk by the New Naval Colliery Co Ltd. in 1880. This colliery sited at the entrance to the Ely valley was the upcast shaft. Nantgwyn colliery or Naval No. 3, Penygraig, Sunk by the Naval Colliery Co Ltd. in 1892. Anthony colliery or Naval No. 4, Penygraig, Sunk by the Naval Colliery Co Ltd. in 1908.

In 1880 over 76,000 tons of coal were raised .

On 10th December 1880 there was a serious explosion which killed 101 miners.

On the 27th of January 1884, another explosion occurred here killing 14 men. It happened on a Sunday when officials where preparing for the next days production. It is thought that shot firing ignited a body of gas.

In 1896 there were 699, 699 and 457 men working at the Naval Nos. 1, 2, and 3 pits respectively, producing Steam coal.v The Naval colliery became amalgamated into the Cambrian Combine Company in 1908.

In 1908 there were 2,080 men employed at the Naval complex of pits.

By 1918 the workforce reached 2,358.

Later it came under the ownership of Powell Duffryn Ltd.

By 1945 only Anthony and Pandy were still in production, employing 578 men.

Ely was kept for pumping only.

Due to the decline in the demand for coal, the colliery closed in 1958 and in 1970 part of the site was made into the Penygraig Rugby Club ground, which has a seating capacity of 5,000.