Chapel off Broad Street.

The Welsh Congregationalists had long worshipped in Blaenavon but it was not until the late 1810s that they financed the creation of their first purpose-built chapel, which was built near Fferm Ty Will Rhios (New Road Farm). The first sermon was held on Christmas Day 1820 and the chapel was named ‘Bethlehem’, in honour of the town of Jesus Christ’s birth. The congregation grew throughout the 1820s and 1830s and eventually a settled pastor, the Reverend Harris, was appointed.

The second minister, the Reverend Thomas Griffiths, was appointed in 1838 and it was decided that the existing chapel was inconvenient and too small. The new, classically styled Bethlehem Chapel was built alongside the quiet stream, the Nant Llechan, in 1840. The interior of the chapel was plain, in keeping with the many early 19th-century non-conformist chapels, although the gallery was supported by eight cast iron piers, demonstrating local pride in the iron industry. The 1840s and 1850s were a time of growth in Blaenavon and soon Bethlehem Chapel was surrounded by a variety of buildings and businesses as Broad Street (or Heol y Nant) was extended along the Nant Llechan.

During the second half of the 19th century, as the English language gained in strength and influence in Blaenavon, Bethlehem Chapel continued to worship in Welsh. Some English-speaking members decided to hold their own services, eventually establishing Lion Street English Congregationalist Chapel in 1867. As the Welsh language declined, Nonconformist chapels across Wales were forced to hold bilingual or English-language services. Bethlehem Chapel, however, resisted this change for as long as possible and continued to hold Welsh-language services until the early 20th century, making it the last chapel in Blaenavon to abandon the native language.