We did a 30 day drive about last summer in Ireland and N. Ireland. We were happily surprised by Belfast. We were there for 4 days and would have liked to stay longer. The Titanic display was awesome as was being able to go on the Titanic's tender. The large shopping malls were clean and well kept and walking about in the city was great. Remember, N. Ireland is on the British Pound, not the Euro. So, if you are from US, the exchange rate for car rentals might be better in Dublin then in Belfast. Also, bus services run from Dublin to Belfast probably every 1/2 hour or so. The bus might be cheaper than car rental and gas if that is all you want to see. If you are going to do a week, then flying into Dublin and driving, as suggested, would be great. Rent your car at the airport, you do not want to drive through Dublin, trust me on this. The scenery is wonderful all around N. Ireland. Look at a map and maybe plan doing a loop Dublin, Belfast, Giant Causeway, Londonderry, Doolin (great trad music), maybe Limereick, arriving back in Dublin the day before you go home. This is not a finite list. Get a map or googlemaps.com and look at the driving times. You might want to break up some of the days by spending time in a small village. Airbnb will be your friend here. Cheap accommodations and try to stay OFF of "L" roads if possible.