The most breathtaking things about Ireland are the ever-rolling green hills and pasture lands that stretch seemingly from one end of the country to the other. The best way to get an expansive feel for why the nation is known as "the Green Isle" is to hop on a train and ride coast to coast. Train fare is relatively inexpensive; in 2009 an adult train fare from Dublin (east coast) to Galway (west coast) sets one back a mere 30 to 40 euros. The train lines pass through cities and towns along the way, but the main views are of grazing sheep in bright green fields that seem to never end. Visit the Irish Rail webstie to check rates and timetables (www.irishrail.ie).
Guinness is perhaps the most well known and loved Irish breweries. The St. James's Gate Brewery in Dublin, first opened in 1759 under the supervision of Arthur Guinness. The factory is impossible to miss. It is located along the Lify River, Dublin's main water way, and is a short walk from the Dublin Heuston train station. Tours are available of the Guinness storehouse (not the brewery) at St. Jame's gate for 15 euros per adult (10 percent discount if you buy online). The self-guided tours are offered seven days a week.
The Irish, as are most Europeans, are steadfast sports enthusiasts in both football (soccer) and rugby. There are many club and regional rugby teams (for locations and schedules visit the Irish Rugby website at www.irishrugby.ie). Ireland's national rugby team plays at Croke Field in Dublin, which is also the location of the Gaelic Games and the home of the Gaelic Athletic Association. For event schedules visit www.crokepark.ie. The energy and atmosphere inside of an Irish sports stadium is undoubtedly a "cool" thing.
Ireland is home to some of Europe's oldest and most majestically "weather-worn" medieval castles. Among the most visited are Trim Castle in County Meath; it is famous for being the largest fortress-style castle in Ireland. Dunluce Castle in County Antrim is located on the northern coast and was formed by the sea cutting into to cliff rocks. Leap Castle, in the Village of Clareen, is considered the most haunted castle in Ireland. One of the oldest castles in Ireland is the Carrickfergus Castle built in 1180. The castle was besieged by the Scots, English and the French all the way up to WWII.
At the end of the day, the "coolest" or rather the most relaxing activity to do in Ireland, is to tuck into a pub or restaurant, and pass away the evening with potatoes cooked any way, and a pint of Irish beer.