Gellionnen Unitarian Chapel was first built in 1692 and rebuilt in 1801. Further alterations to the doors and windows tookm place in 1870-3 and cement render was added during the mid twentieth century. The present chapel, dated 1801, is built in the Simple Round-Headed style of the long-wall entry type. Gellionnen is now Grade 2 Listed as one of the oldest surviving chapels in the region.

RCAHMW, August 2010