The Shannon

The mighty river Shannon is the longest river in Britain and Ireland, at 386 km. It flows south from its source in Cavan through or between eleven counties, dividing the west of Ireland from the east, before meeting tidal water at Limerick city and emptying into the Atlantic Ocean through the 113 km long Shannon Estuary.

The Shannon is named after Sionnan, who was the granddaughter of the mythical Manannan Mac Lir, or God of the Sea. This important river and its tributaries drain about one fifth of the area of Ireland. The Shannon rises in the 8083492315_56a9e5546b_zShannon Pot, a small pool on the slopes of Cuilcagh Mountain in County Cavan, from where the river runs through or between 13 of Ireland’s counties and three provinces – Munster, Leinster and Connacht. Major lakes on the Shannon include Lough Allen, Lough Ree and Lough Derg. Tributaries include the rivers Inny, Suck and Brosna. The river has several associated canals, most famously the Royal and Grand Canals which link the Shannon to the Irish Sea via Dublin. The other most notable canal joins the River Shannon with the Shannon – Erne Waterway System.

Nature on the Shannon

The River Shannon and Lough Derg provide rich habitats for wildlife and plants, with Lough Derg’s northern shores of particular interest due to the limestone rock of the area. Water lilies and hemp agrimony can be found in the reedbeds; rushes, grasses and sedges in the fens bordering the river & lake and buckthorn, spindle and Irish whitebeam along the rocky shores.

The Shannon system also provides habitat for a diversity of birdlife. The endangered corncrake is its most famous summer visitor. However it seems that the corncrake population in the Shannon Callows may have lost their fight for survival as no breeding pairs have been recorded in several years. The callow lands flanking the River Shannon, the River Suck and the River Little Brosna are all of international importance for wintering waders, as well as being of national importance for the 14536472906_633c1baf3b_znumber of breeding waders they hold. They contain 10% of Ireland’s breeding Redshank population, and nationally important numbers of Lapwing, Snipe and Curlew. The recent reintroduced of the White Tailed Sea Eagles from Norway after an absence of over 100 years is bringing welcome eco-tourism to Mountshannon, Lough Derg. It is hoped that a viable population will establish its self along the Shannon and Erne Systems.

Enjoying the Shannon


The beauty and ease of navigation of the Shannon, along with its excellent lakes means the Shannon is the centre for inland water sports in Ireland.  There is a significant tourist market for boat rentals during the summer as beginners can cruise large sections of the river without having to go through any locks.  The Irish Inland Waterways Association of Ireland (IWAI) publishes maps for navigation on the Shannon and educates users about safety and environmental concerns.


The Shannon is ideal for canoe touring and kayaking. You can learn more about navigation of the waterway here.


The River Shannon with its numerous islands, backwaters, pools, bends and quiet bays, in addition to open lakes, forms an enormous and richly diverse fishery, which holds great stocks of a wide variety of fish including salmon, brown trout, bream, tench, rudd, roach, hybrids, eels, pike and perch. See for more information of fishing on the Shannon.


The Shannon river is closely bound up with Ireland’s social and cultural history. Vikings settled in the region in 10th century and used the Shannon to raid the wealth of the monasteries inland. In preparing a land settlement, after his conquest of Ireland, Oliver Cromwell reputedly said the remaining Irish landowners would go to “Hell or Connacht”, referring to the option of forced migration west across the river Shannon, or death, thus freeing up the eastern region for the incoming English settlers.


In the latter part of the 1820s, trade increased dramatically with the arrival of paddle-wheeled steamers on the river which carried passengers and goods but in 1849 a railway which opened between Dublin to Limerick led to a dramatic drop in freight and passengers numbers. In the 1950s when traffic began to fall even further, the Inland Waterways Association of Ireland persuaded the government to keep bridges high enough for navigation and since then leisure boating and cruising has steadily increased on the Shannon, becoming a great success story.

One of the first projects of the Irish Free State in the 1920s was to build the Ardnacrusha hydroelectric generation plant on the lower Shannon near Killaloe. This is still run by the ESB as is the huge coal-fired electricity plant on the Shannon at Moneypoint, near Kilrush in Co. Clare which opened in 1985.

In 1982 a large scale alumina extraction plant was built at Aughinish Island on the Shannon estuary. 60,000 tonne cargo vessels now carry raw bauxite from West African mines to the plant, where it is refined to alumina before being exported to Canada where it is further refined to aluminium.