1 city to travel to. where to go

Me (27M) and my father (60) will be traveling to Dublin at the end of August/beginning of September. We have 2 spare days to fill and can’t decide where to go outside of Dublin.

Please help me choose where to go.

Some background: don’t want to do too much hiking (bad knee) and we enjoy drinking. I still want to see things so walking isn’t out of the question just can’t do miles and miles. We can rent a car so assume transportation is not an issue.

Right now I’m thinking Dingle, Galway, Killarney, or Belfast.

Also please recommend can’t miss things in Dublin/Ireland. Going to spend plenty of time in pubs is the main plan.

All the best and thanks for the help in advance!