Bovagh Bridge, Mullaghinch Road, Agadowey, Coleraine, Co Londonderry, BT51

Bovagh Bridge is a four-arched masonry bridge carrying a road over the Agivey River in open countryside. The structure is constructed throughout of random rubble basalt. It is possibly of 16th century origin, though this remains unverified, and was widened to its present form around 1796.

The bridge consists of four segmental arches, with the middle two (arches 2 and 3) being slightly wider than the end ones. The first arch on the left (northern) bank is now dry, having been blocked by a mid-19th century water-powered flax mill immediately to its west. Arches 2 to 4 span the river proper, which descends through a series of shallow rapids at this point. Angled cutwaters project from both the upstream and downstream ends of the piers, rising to arch spring level.

The abutments and piers of the river spans are underpinned with concrete. Physical evidence of the widening is visible in breaks in all arch soffits, showing the bridge was enlarged by 8 feet at its upstream end, increasing from 13 feet to its present width of 21 feet. Two metal tie bars have been inserted through each arch just above the voussoirs. The spandrels have been heavily repointed. The parapets have been rebuilt—their rubble basalt stonework differs slightly from the rest of the bridge and has been brought to courses. The downstream parapet is slightly advanced beyond the spandrels, and both are coped with concrete. A modern steel plaque at the southern end of the eastern parapet names the bridge and river. The deck has a slight curve, and the right bank has been faced with stones both upstream and downstream from the bridge.

An 1836 Ordnance Survey Memoir describes the bridge as having spans of 13 feet 8 inches, 20 feet 6 inches, 20 feet 6 inches, and 13 feet 6 inches (from north to south), with a roadway width of 19 feet and parapets 3 feet high but in bad repair. The memoir states the bridge was built approximately 300 years prior (suggesting early 16th century date) and made broader in 1796. The present structure's spans match those in the memoir, and physical evidence confirms the widening documented at that time. The bridge is shown on the 1832 Ordnance Survey six-inch map and is named on the 1853 edition and subsequent maps.

The setting includes woodland to the east and southwest. Adjacent to the bridge at the northwest is a two-storey mid-19th century water-powered flax mill, probably dating from the 1840s or early 1850s and now refurbished for other uses. The mill is aligned north-south at right angles to the river and has a pitched natural slate roof with plastic ogee rainwater goods. Its walls are of random rubble with a brick eaves course and brick apex to the south gable. Openings to the east and west elevations have been infilled, some trimmed with brick, and doorways are present to the ground and first floors on the north gable. At the north end of the approach road from the north is a small culvert for the mill's tailrace, now infilled except for its arch crown visible on its west face. The mill's headrace, which formerly entered at the north end of the west side, has been infilled to create a small gravelled car park for use by anglers.