Complex sentence: Senghenydd--in Welsh--at the northern end of the Aber Valley, approximately four miles north-west of Caerphilly, was a farming hamlet of around 100 people in 1890 when geological surveys for coal began.
Split into simpler sentences: Senghenydd--in Welsh--is situated at the northern end of the Aber Valley approximately four miles north-west of Caerphilly. It was a small farming hamlet of around 100 people in 1890 when geological surveys for coal began.