The Sirhowy river rises to the north of Tredegar before turning to flow south-easterly where it links with the Ebbw river at Cross Keys.
Below its surface and the hills which surrounded it ironstone, limestone, coal and wood were discovered and with them an industrial explosion of activity which h was to change the whole of Blaenau Gwent for ever (if, at times, not for better). Those four natural products were perfect for iron-making and there is some suggestion that that started in this area as far back as 1597! It was 200 years later that the famous, neighbouring, Tredegar iron works transformed the local area. (see Tredegar).