Sirhowy Ironworks, Tredegar were first established in 1778. From 1818 Sirhowy supplied Ebbw Vale Ironworks with pig iron. In 1844 there were five furnaces. By 1877 the amount of iron cast was more than could be contained in the cast houses and they were partly demolished. After ironmaking ceased at Sirhowy c.1883 it continued to produce coke for Ebbw Vale until finally closing in 1905. The principal remains of the site include three masonry charging platform arches, the base of a furnace, waterwheel supply tunnel and various earthworks.
The site is a scheduled ancient monument and is open to visitors.