The Kilnap Viaduct (known colloquially as the Eight-Arch Bridge) is an eight-arch railway viaduct located in Cork, Ireland.

Built in 1845, it carried the Great Southern & Western Railway line to Cork over the valley of Glennamought River and Mallow Road.

[1] The viaduct is listed as a protected structure by Cork City Council.

[2] The eight-arch railway viaduct features rock-faced ashlar limestone piers with a cut stone impost supporting squared coursed limestone spandrels with dressed limestone string course.

It has rock-faced limestone voussoirs leading to round-headed arches, ashlar limestone vaults to barrels and a squared coursed limestone parapet with cut stone coping.