Llanthomas House, Llanigon, was a former long-house. A bryre and barn were added added in the 19th century to give an L plan. The house was replaced by a mansion in the 19th century, which was 3 storey with a stone portico supported by columns. Now demolished.

Source: early black and white postcard, undated.

RCAHMW, 7th December 2007.