New Bridge, Merthyr Mawr, is a single-carriageway road bridge of coursed, hammer-dressed stone, ramped to the centre. The abutments are wider than the deck and have rounded angles. The three segmental arches have projecting keystones, and the V-shaped cutwaters are stepped up to a projecting band at the base of a low parapet. The parapet has flat coping and terminates with square piers (with later stone walls attached).

On the upstream side is a tablet set into the parapet and inscribed: "This Bridge was built and finished at the expence [sic] of the Right Honourable Sir John Nicholl under the inspection of William [Whirlington?] Country Surveyor by Morgan Thomas of Laleston AD 1827"; Nicholl had purchased the Merthyr Mawr Estate in 1804 and built a new mansion for himself, for which he appropriated the original road to Merthyr Mawr village as his private drive. A new road was therefore adopted, requiring a new bridge across the River Ogmore. The present bridge replaced an earlier bridge with a wooden deck on stone piers which had been erected early 19th century.

Reference: Cadw listed buildings database.