The River Shannon is the longest river in the Republic of Ireland and on the island of Ireland at 360.5 kilometres long. It drains the Shannon River Basin which has an area of 16,865 km², one fifth of the area of the island. The Shannon divides the west of Ireland from the east and south and flows through 11 counties including Longford. The River Shannon means ‘wise river’. It is named after Sionnan, the granddaughter of Manannán Mac Lir (Son of the Sea), a sea deity in Celtic mythology. Sionnan means “possessor of wisdom” and the Irish name for the River Shannon is Abhainn na Sionainne. Sionainn is a combination of the words ‘sion’ (wise) and ‘abhainn’ (river). The source of the River Shannon is the Shannon Pot in the Cuilcagh Mountains in County Cavan.
The Grand Canal in Dublin begins at Grand Canal Dock at the River Liffey and flows 131km through the south and west of Dublin before meandering into County Kildare and crossing into County Offaly where it links to the River Shannon at Shannon Harbour. The idea for a canal linking the capital city with the longest river in Ireland was proposed in the early 1700s but the Grand Canal didn’t officially link to the River Shannon until 1804.
Shannon River flowing through Lanesborough - photo by Shuttermaniac Photography
The River Shannon is also linked to Lough Erne in County Fermanagh in Northern Ireland. Navigation between the North and South of Ireland is now possible via the Shannon-Erne Waterway. There are three main lakes on the River Shannon. The uppermost lake is Lough Allen in County Leitrim, although some of the lake is located in County Roscommon. Lough Allen is the smallest of the three main lakes on the River Shannon.
The next biggest lake on the River Shannon is Lough Ree, which separates counties Longford and Westmeath in the east from County Roscommon in the west. The most southerly, and also the largest lake on the River Shannon is Lough Derg. The shores of Lough Derg touch counties Clare, Galway and Tipperary. There are other smaller lakes on the Shannon dotted along its course including Lough Bofin, Lough Boderg and Lough Forbes.
Some parts of the River Shannon are actually quite shallow with a depth of about 0.5 metres in places. It falls just 18 metres (59 feet) in the first 250km (160 miles) of its course. It rises only 76 metres (249 feet) above sea level at its highest point meaning that it isn’t very deep at all and as a result, the river moves quite slowly. The River Shannon is home to plenty of fish too and there is an abundance of fishing hotspots and coarse angling areas. In the River Shannon, you’ll find brown Pike, Bream, Perch, Roach, Rudd and Tench.
The River Shannon is ideal for lock-free boating holidays - with no commercial traffic, and only 6 locks in its 220 kilometres of cruising water. The river and the lakes flow through natural landscapes and historic sites - they are also an angler's paradise. See boating.
Navigation map of the River Shannon