Nelson is a village and community in the county borough of Caerphilly, Wales. It sits five miles north of Caerphilly and ten miles north of Cardiff, at the lower end of the Taff Bargoed Valley, and lies adjacent to Treharris, Trelewis and Quakers Yard.
Nelson was originally called Ffos-y-Gerddinen, a relatively flat piece of land at the southern extremity of the Taff Bargoed Valley to the south of the hamlet of Llancaiach. It existed on a drovers trail from the South Wales coast towards Merthyr Tydfil and onwards to Brecon and Mid Wales, where an enterprising man built a coaching inn that he called Nelson, possibly after Admiral Lord Nelson and his victory at the Battle of Trafalgar. Had it not been for the development of the South Wales coalfield, Nelson would have remained just a coaching inn surrounded by fields. When the Llancaiach Colliery was developed from 1811, it created a need for new housing for the workers and heavy transport for the coal, which spilled onto the flat lands below the colliery.