 When the Taff Vale Extension railway of the Newport, Abergavenny and Hereford Railway was built, it replicated the TVR naming convention for its station, and Nelson was born as a village with a separate identity to Llancaiach.Nelson is situated at above sea level in a natural basin close to the confluence of the Taff and Taff Bargoed valleys, and the resultant relative flatness and surrounding fields are quite atypical of the steep sided valleys and linear villages associated with the area.To the south the land rises gently to the 383 metre summit of Mynydd Eglwysilan, which offers panoramic views of the Brecon Beacons, Bristol Channel and the coasts of Devon and Somerset.