Kilnap Viaduct, Railway viaduct in Cork, Ireland

Kilnap Viaduct, known locally as the Eight-Arch Bridge, is a railway viaduct of eight round-headed arches in Cork. Its rock-faced ashlar limestone piers carry squared coursed limestone spandrels, a dressed limestone string course and a parapet with cut stone coping. As built it measured 420 ft long and 90 ft high.

Built in 1845 by William Dargan for the Great Southern & Western Railway, the viaduct carried the line over the Glennamought River valley and Mallow Road on the Dublin–Cork route. It is still in use on that same main line and is listed as a protected structure by Cork City Council.

Locals call it the Eight-Arch Bridge, counting the round-headed limestone arches that carry the line over the Glennamought valley. The viaduct is a protected structure under Cork City Council, and trains on the Dublin-Cork line still cross it daily.

The viaduct can easily be seen from the road and viewed from several points nearby. The best views come from Mallow Road or the paths along the river valley.

Kilnap Viaduct is known locally as the Eight-Arch Bridge, a name that counts the round-headed arches carrying the line over the Glennamought valley. As built it measured 420 ft long and 90 ft high, and it is listed as a protected structure by Cork City Council.