A branch of Nebo, Ystrad Rhondda, it began when a vestry was established in September 1866.
Reportedly seating 1,000, it had an unusually ornate interior for a Welsh chapel, with a stained glass window of John the Baptist in the lobby, three aisles, an 'all-round' gallery, and a three-manual organ, and has been described as "the Rhondda Valley's cathedral of nonconformity" [REF].