Hello! I'm planning a trip in late May to Ireland, and I'm struggling with the journey from Dingle to Dublin. My boyfriend wants to go to Blarney Castle, and I'd like to see the Rock of Cashel, AND we'd like to get to Dublin reasonably expeditiously. I am planning that we can't do all of that in a day, and will therefore need to stop. For those of you who've done the trip... would you recommend stopping in Cashel? Or should we travel further on before stopping so we can get into Dublin in the morning? We're only spending one night there before heading off to Scotland, so we'll only really have two half days as it is.
Dingle and Blarney are about three hours' drive apart. Blarney and Cashel are a couple of hours apart. You could probably easily get to Blarney, see what you want to see there, and then get to Cashel for the night (though you might want to stop in Cahir and see the castle there, too). Rock of Cashel to Dublin is slightly less than a three hour drive, if that helps you. By starting out early each of the two days, you should be able to do everything you would like to do.
Totally agree with Nancy's comments. We basically did what you are proposing except backwards. We went from Dublin - spent the night in Cashel. Near as I remember the Dublin to Cashel drive was about 2 1/2 hours. Next day we drove from Cashel to Killarney to see the Muckross House before ending up in Dingle. I would say the drive from Cashel straight to Dingle is about 2 1/2 hours as well. It's hard to be exact because we stopped for a lot of pictures. You'll absolutely love Dingle. It's been rated one of the top 10 destinations of all of Europe.
I've also done the reverse drive. Leaving Dingle after a leisurely morning and some shopping we did Muckross house and gardens and made Cashel before dark. We did the Rock of Cashel first thing in the morning then went onto Dublin to easily make an early afternoon flight. The drive from Cashel to Dublin is essentially all freeway and was really fast. I have heard good things about the castle in Cahir but I haven't been there or Blarney so I don't have any comparisons but the Rock of Cashel got crowded really quickly. The window of our BnB looked up at the Rock so we were there absolutely first thing but so we had to ourselves for a bit but there we busses jockeying in the street by the time we left. I can't imagine Blarney is any less crowded but you might factor crowds into your site scheduling. Have a great trip,