Hi there - Dublin is my home town and I am always so jealous of people visiting there! With such a short visit I would recommend using taking a short 8 day Shamrocker adventure because it takes in the entire country - Dublin, Belfast, Giant's Causeway (my favourite) the Burren, Dingle, Killarney, Blarney Castle and a whole lot more. They book your accomodations for you along the way, so it's guaranteed but you pay as you go and you get to meet tons of cool people. Give me a call if you want any other ideas, and have a super trip!