Shannon River Basin a measurement of . When added to the Shannon's estuary this gives a total river flow of , which makes it the longest river within the River Shannon basin (from source to mouth)— longer than the Shannon Pot source. Thus the Boyle-Shannon river can be regarded as having the longest natural river flow in Ireland. The River Shannon Basin touches more than half (17) of Ireland's counties:- Limerick, Clare, Tipperary, Offaly, Westmeath, Longford, Roscommon, Kerry, Galway, Leitrim, Cavan, Sligo, Mayo, Cork, Laois, Meath and Fermanagh. There are many towns situated in the Shannon Basin. Towns and Villages (with 2011 populations)
Books of Survey and Distribution include: "Proprietors in 1641 by the Civil Survey", "Denominations of lands by the Downe Survey", "Number of acres distributed", "persons to whom distributed" and "Rent per annum payable to His Majesty". The surviving Survey and Distribution volumes cover the following counties: Kilkenny, Waterford, Kerry, Kildare, Carlow, Wexford, Longford, Mayo, Tipperary, Monaghan, Armagh, Limerick, Westmeath, Clare, Roscommon, Galway, Cork, Down, Antrim, Leitrim, Sligo, Cavan, Fermanagh, Laois, Offaly, Wicklow, Donegal, Londonderry and Tyrone. The Books for Clare, Galway, Mayo and Roscommon have been published by the Irish Manuscripts Commission. For other counties, manuscript copies are available at the National Library.Those for co