The main river in Ireland is the River Shannon, 386 km (240 mi), the longest river in either Ireland or Great Britain, which separates the boggy midlands of Ireland from the West of Ireland. The river develops into three lakes along its course, Lough Allen, Lough Ree, and Lough Derg. Of these, Lough Derg is the largest.
Favorite Irish drinks - "When in Rome ..." applies to any place in the world, really. Especially when it comes to food and drink. True, you can survive an Irish holiday on Big Macs and Coke (or Whoppers and Pepsi, for the sake of variety). But will you really have experienced the local cuisine? No - and going into a pub and drinking just Bud Light should be positively discouraged. If you want to down a few, why not try the local brew?