Knockanboy Bridge

Single-arch humpbacked canal bridge carrying road over Royal Canal (Longford Branch), built c. 1829. Round/elliptical-headed arch with dressed ashlar limestone voussoirs and dressed limestone masonry to barrel. Dressed limestone spandrel walls with cut limestone string course at road/deck level. Dressed ashlar limestone parapets with curving ends terminated in dressed ashlar limestone piers (on square-plan). Dressed ashlar limestone coping over parapet walls. Rubble stone construction to inner faces of parapet walls. Towpath to west bank of canal. Dressed limestone retaining walls to canal banks (east and west). Located to the southwest of Longford Town.

A typically well-built canal bridge, which is a valuable part of the architectural and industrial heritage of County Longford. Although humble in form, this structure has a simple and functional elegance. It is robustly built in fine stone masonry, which is testament to the long-term ambitions of the Royal Canal Company at the start of the nineteenth century. It was probably built to designs by John Killaly (1766 – 1832), the engineer responsible for the construction of the Royal Canal (Longford Branch), which was surveyed in 1826 and opened in 1830. The main contractors involved were J.J. Byrne and William Tarrent. Although the canal is currently disused, the towpath provides a recreational amenity and this bridge affords interesting views to the pedestrian as well as being a notable feature and landmark in the landscape. This bridge forms part of an extensive collection of canal-related structures in County Longford, and is an integral element of the built heritage of the local area.