Will be flying to Dublin with family in early June, has 3 days. We wanted to explore Dublin in 1 day then maybe do a day trip to Belfast the next day. Any suggestions on what to see in Northern Ireland, like Belfast and maybe Giant Causeway? Or is it better to stay in southern Ireland and explore the outskirts of Dublin like Blarney Castle, the famous Rock, etc. Any suggestions to do in a short time will be highly appreciated.