The bridge is first documented in 1538[3] and is believed to have existed since medieval times, originally constructed from timber.[4] In 1706 it was completely rebuilt in stone with additional arches,[3] at a cost of £400. It was replaced by a temporary bridge in 1808 after being severely damaged by flooding[4] and the repaired bridge, in 1810, was widened on the northwest (upstream) side (the downstream side remains original to 1706).[3] The bridge engineer was Benjamin James (of Llangattock) and the cost totalled £2,300.[5] In 1828–30 the northeast end was altered, reducing the upstream length by one arch[3] by combining the two largest upstream arches into one.[6] The bridge was substantially repaired in 1928 and again in 1979, to repair cracking caused by motor vehicles.[4] In 2011 part of the parapet was demolished by a car, following a police chase.[7]
Crickhowell Bridge is unusual (due to the 1828 alterations) in that it has a different number of arches upstream (12) from downstream (13).[4] On the (original) downstream side, the arches are recessed, though not on the upstream side. The bridge has V-shaped cutwaters to both sides with pedestrian refuges above. Construction is of rubble masonry with flat coping stones on the parapets.[3] The bridge is 128 metres (420 ft) long and has a minimum width of 4 metres (13 ft) between parapets.[6]
