TheEsker Riada (Irish:Eiscir Riada) is a system ofeskers that stretch across the middle ofIreland, betweenDublin andGalway.
The Esker Riada is a collection ofeskers that passes through the counties ofDublin,Meath,Kildare,Westmeath,Offaly,Leitrim,Longford,Roscommon andGalway. A large remnant of the Esker exists in the Teernacreeve region of Westmeath, and stretches from Kilbeggan to Tyrrellspass.
The eskers take the form of relatively low-lying ridges composed of sand, gravel and boulders deposited by water flowing beneath a glacier that became exposed when the glacier melted at the end of the last ice age, around 10,000 years ago.
The Irish nameEiscir Riada provides an indication of the significance of the eskers. The first element (and Englishesker) comes from Old Irishescir meaning "a ridge, an elevation (separating two plains or depressed surfaces)" and the second is from Old Irishríad which refers to "riding, driving" (later "taming") of the horses or oxen driven on it.[1][2]
Following a battle atMag Lena, in the second century, the island of Ireland was divided into two political entities along the line of the eskers – ‘Leath Cuinn’ (‘Conn’s Half’) to the north, and ‘Leath Mogha’ (‘Mogha’s Half’) to the south.[3]
Because of its slightly higher ground, the Esker Riada provided a route through thebogs of the Irish midlands. It has, since ancient times, formed a highway joining the east and west of Ireland. Indeed, its ancientIrish name is ‘An tSlí Mhór’, meaning ‘The Great Way’.[3][4]
TheSlighe Mhór ('Great Highway') provided a link betweenClonard Abbey,Durrow Abbey and the monastic settlement ofClonmacnoise, constructed at the point where theRiver Shannon passes through the Esker Riada.[3][5]
In contrast with the surrounding boglands, the glacial sands typical of the eskers provided well drained and relatively good quality land, proving useful for agriculture.[6]
To this day, the Esker Riada continues to serve as a highway, the mainN6Dublin toGalway road still closely following it; and much agricultural activity still takes place along its length. The Dublin part begins at High Street, beside Wood Quay, site of the Viking settlement and original ford made of hurdles, or basketwork, that gives Dublin its name(Átha Cliath), and follows southwest through Kilmainham to Greenhills Road.
The eskers have become a valued source of building material, with sand and gravel extraction being commonplace. However, the negative environmental impact of such operations is now being realized and this, along with a developing awareness of the ridge and its significance in Ireland’s history, has led to increasing restrictions.[citation needed] Indeed, Offaly County Council has moved to give the ridge protection in its County Development Plan, and has gone so far as to press to have the Esker Riada recognized as aWorld Heritage Site.[7]