The Sirhowy Valley lies north of Risca and south of Tredegar in South Wales, along the River Sirhowy. Early history shows that the area was mainly farmland with a few iron ore workings and furnace sites towards the northern end of the valley. In addition there were many quarries working a variety of minerals from sandstone, millstone through to shales. Prior to the introduction of coke the numerous iron works in the valley were supplied with charcoal from the nearby woods. Another important natural resource in the area was to be found in the hills around Trefil were rich in carboniferous limestone. Limestone and its derivative lime were much needed commodities. Crushed limestone was use as a metallurgical flux in the smelting of iron ore while burnt lime had important uses in agriculture plus the manufacture of mortar.

Coal was first worked along outcrops in the valley by the miners digging shallow tunnels otherwise known as "adits" or "slopes" which followed the coal seams into the hillsides. The coal was subsequently loaded into baskets made of interwoven twigs and hauled from the tunnels by women or children. The tunnels were driven into the hillsides at a slight incline to allow the drainage of ground water from the mine workings.

During the late eighteenth century there were already a few coal levels working in the Sirhowy Valley. However, it was until the early in the next century that industry in the area was to really take-off with the valley changing forever with clouds of furnace smoke billowing along its length. During this same period the mines of the Rhondda, Cynon and Taff Valleys together with other areas of Monmouthshire were also expanding to meet the needs of the country’s rapid industrial expansion. Coal was not only needed to fuel the new steam engines that powered the industrial revolution but also (in the form of coke) the large number of blast furnaces that were trying to keep pace with the nations new found and insatiable demand for iron and steel.

In 1800 the Tredegar Iron Company (T.I.C.) was formed which after 1873 operated under the title of the Tredegar Coal & Iron Company (T.I.&C.C.). To keep pace with the production from the T.I.C.’s iron furnaces new collieries began to be sunk to supply the endless amounts of coke needed to fuel them. One of the first deep mines in Wales was sunk in 1806 at Tredegar by the T.I.C. This mine was known as "The Dukes Pit", after the Duke of Beaufort on whose land it was sunk. Another pit, Pwll Mawr, at Neath was sunk at about the same time.

All along the Sirhowy Valley the need for coal was becoming greater as iron works and industry became more intense. More coal was being transported down the valley further towards Newport. This increase in demand gave rise to further collieries being opened in the southern end of the valley which in turn required the opening of new railway branch lines to convey the "Black Gold".

Pochin Colliery a little further to the south was sunk in 1876 and continued in production until 1968. The colliery was named after Laura Pochin, a daughter of one of the directors of the T.I.&C.C. At the peak of its production in 1910 this mine employed 1700 workers and was one of the first collieries to use compressed air.

Another Sirhowy Valley colliery was Abernant (not to be confused with the mine of the same name in the Swansea Valley). Abernant was sunk by the Bargoed Coal Company in 1880 and had two shafts, East and West Pits. Abernant later became linked underground to a neighbouring colliery at Llanover. In 1890 over one thousand bags of coal were sent to consignees everywhere to advertise the fact that Abernant Colliery produced the best "smiths" coal in Wales. Abernant Colliery raised its last coal in 1932 and by 1934 was being maintained purely as a pumping station to assist in the drainage of  neighbouring pits.

Other pits of note in the Sirhowy Valley included;

• Graham Brothers Navigation Colliery (a.k.a. Sirhowy No.9  or First Class Pit), 1840-1924. Sunk by the Ebbw Vale Steel & Iron Company to supply the Sirhowy Iron Works. In 1913 the pit passed into the hands of the Graham's Navigation (Merthyr) Company Ltd.
• Witworth Colliery, 1876-1959. Sunk by T.I.&C.C. and amalgamated with Ty Trist in 1959.
• Bedwellty Pits, mid 1800s-1930s. This series of pit were worked by the T.I.&C.C. and consisted the No.1 & No.2 Pit plus the No.1 & No.2 Levels. In July 1898 the pits were link to the newly opened McLaren Colliery.
• Rock Colliery, 1878-1957. Sunk by the Rock Coal Company consisting of two levels and two pits.
• Hollybush Colliery, 1880-1921. Sunk by E.D. Williams of Blackwood.
• Markham Colliery, 1910-1985. Sunk by the Markham Steam Coal Company, a subsidiary of the T.I. & C.C. 

• Oakdale Colliery, 1907-1989. Sunk by T.I.&C.C.  In 1979 Oakdale’s workings were linked to those of Markham and later in 1981 to Celynen North Colliery. By this time the combined pit had a workforce of 2000.

• Wyllie Colliery, 1926-1968. Sunk by T.I.&C.C.
• Nine Mile Point, 1902-1964. This mine was originally known as Coronation Colliery and was sunk by Burnyeat, Brown & Company. The mine later became known as Nine Mile Point as this was its distance from Newport Coal Docks on the route taken down the valley by the Sirhowy Wagon Way. 

• Waterloo Colliery, 1908-1970. Sunk by the Oakdale Navigation Colliery Company Ltd., a subsidiary of the T.I. & C.C. 
• Risca Colliery or New Black Vein Colliery, 1878-1967. Sunk by the London & South Wales Coal Company Ltd. who reformed in 1892 as the United National Coal Company. However, by 1926 the pit had passed into the control of the Ocean Coal Company.
• Black Vein Colliery, 1841-c.1935. Sunk by John Russell who later formed the Risca Coal & Iron Company in 1847. By 1866 the pit was in the possession of Thomas Rhodes and later in 1872 passed into the control of the London & South Wales Coal Company Ltd. By 1888 the colliery had ceased production as a fully working pit and after the sinking of Risca Colliery became known as the Old Black Vein Colliery. The ownership of the pit remained the same as that of the Risca Colliery until it finally closed some time shortly after 1935.