Arch, Piers of Old Br. — Coldblow,lucan Demesne

One of three bridges (DU017-019006-/007-) that spanned the River Liffey in the vicinity of the town of Lucan. A medieval bridge traversed the River Liffey at the meeting point between the Liffey and the River Griffeen adjacent to Lucan House possibly built on the site of Lucan Castle (DU017-019001-) and the medieval parish church (DU017-019002-) located on the S bank of the Liffey. This bridge was annotated 'Lucan Bridg' on the 17th century Down Survey Map of Newcastle Barony where it is shown cross the River Liffey to the N of Lucan House and the medieval parish church (Hib. Reg.). The Down Survey map of Lucan Parish shows 'Lucan Bridge' as a multi-arched humpbacked bridge traversing the River Liffey adjacent to Lucan House (NLI, MS. 714). The 1654-56 Civil Survey of Dublin recorded that at; 'Lucan there is a verry faire house a Chappell some thatch houses and Cabbins and a good Stone bridge crossing the river Liffey' (Simington 1945, 290). Remains of the bridge were indicated on the 1837 ed. OSi 6-inch map and the remains were annotated 'Piers of Old Br.' and 'Arch'. The bridge is shown on Rocque's 1760 Map of County Dublin. A single, pointed, segmental arch, is all that survives of this bridge. The remains are on the grounds of a house formerly called 'Bleach Green', now 'Treeslips'. It is well-built of coursed limestone blocks with a cut-water present on the upstream side. This bridge was described by Henry A. Wheeler of the National Monuments Service in 1977 as; 'One arch belonging to north end of medieval bridge survives. The roadway was narrow with a cut-water. To the N of it is an 18th-century mill-race continuing the line of road which crossed the bridge (SMR File 12/09/1977). The Urban Survey of Dublin (Bradley and King 1988, 253) recorded the following details about the bridge in the medieval manorial borough of Lucan; 'This is first mentioned, as far as we have been able to ascertain, in the seventeenth century (Ball 1902-20, iv, 43). The absence of flanking burgage plots along Bridge Street indicates that it is an insertion and was not part of the original pattern'. According to Simington and O'Keeffe (1991, 270), 'the first known reference to a bridge is in 1456 in the Statute Rolls under 34 Henry VI which prescribed that 'two towers with two gates be made, one upon the bridge of Kilmainham, another upon the bridge of Lucan' The fortified bridge was to prevent incursions by "Irish enemies and English rebels" into Fingal by night. See attached Down Survey map of Newcastle Barony showing Lucan Bridge courtesy of the Library of Trinity College, Dublin and the Down Survey map of Lucan Parish which shows Lucan Bridge as a humpbacked bridge traversing the River Liffey, courtesy of the National Library of Ireland. NLI, Ms. 714 National Library of Ireland, The parish maps of the Down Survey for the County of Dublin by W. Petty (1657). Copied by Daniel O'Brien. A set of 42 maps with accompanying terriers, copied in 1786-7. Compiled by: Geraldine Stout Updated by: Christine Baker Revised by: Caimin O'Brien Date of revised upload: 9 May 2023