Newport Arch is a 3rd-century Roman gate in the city of Lincoln, Lincolnshire. It is a Scheduled monument and Grade I listed building and is reputedly the oldest arch in the United Kingdom still used by traffic. The arch was remodelled and enlarged when the city, then Lindum Colonia a Roman town, became capital of the province Flavia Caesariensis in the 4th century. Though unique in the United Kingdom, it is nevertheless one of many original Roman arches still open to traffic, other examples being two gates through the city walls of the Roman town of Diocletianopolis (now Hisarya, Bulgaria), as well as numerous examples in Turkey. As the north gate of the city, it carried the major Roman road Ermine Street northward almost in a straight line to the Humber.
In the fourth century, the city walls were strengthened, and at that time Newport probably consisted of a central arch for traffic, flanked by two smaller pedestrian arches. An upper floor topped the archway, and the whole structure was flanked by twin towers. The whole structure would have risen to a height of 26 feet above ground level. The arch as we see it today is merely the upper section of the inner arch; the outer section was destroyed in the 17th century. There is no record of any attack upon the arch or the city walls during Roman times, though the gates here were attacked in the 13th century, during the Battle of Lincoln Fair.
One of the most perfect and interesting of Roman remains is the archway at Lincoln, known as “Newport Gate,” and styled by Dr. Stukely “the noblest remnant of this sort in Britain.” It was the north gate of the Roman city of Lindum, and from it a military way, called the Ermine Street, leading to Winteringham on the Humber, may now be traced, and it still forms the principal entrance into the city from the north. It is supposed to have had a large central arch, and two smaller ones at the sides, that on the west having been destroyed, the larger being about fifteen feet, and the lesser ones seven feet in width. It is built of square stone, out as far as the top of the arch, of remarkably large size. It is without ornament of any kind, but is said by Rickman to have had architrave and impost mouldings. That of the architrave, if it ever existed, has entirely disappeared ; but there is, or was lately, a small portion of the impost moulding remaining, on the west side of the large arch.
“Cassell’s Illustrated History of England”, 1865, p.20
A considerable portion of the north gate of Lincoln — the Newport Arch — is standing, but is buried to the extent of about 8 ft. in the soil and debris accumulated since Roman times. The structure is about 34 ft. deep and has a single passage for the road, 17½ ft. wide. The inner or back portal of this passage is still intact, and is nearly 16 ft. in the clear and rises to a height of about 22½ ft. above the Roman level. Its arch is of a single ring of large limestone voussoirs rising from imposts which appear to have been moulded. The outer or front arch has long since disappeared. On the east side is a postern for pedestrians, 7 ft. wide and contracting to about 5 ft. at the north end, and 15 ft. high from the Roman level. On the west side there was a similar postern about a century ago. The whole structure is of good masonry, and it appears to have projected considerably beyond the north face of the town wall.
“Romano-British Buildings and Earthworks”, John Ward, 1911, p. 72