Kilarney National Park

Killarney is one of the few places in Ireland I don't care for. It's overdeveloped, commercialized beyond belief and is seemingly designed for extorting every last penny from tourists. Leprachauny gift shops compete with American chains and stereotyped Irish stuff......and the traffic often stinks.

HOWEVER there is fantastic stuff just outside the city that is truly fantastic and well worth visiting. The Gap of Dunloe, Ladies View, Ross Castle, Torc Waterfall, the Black Valley, Bally Beama Pass (not for the fainthearted). You can see all these and avoid much of the city. It's a wonderful area. Just urge you to minimize Killarney proper as much as possible. Rick rightly nailed it as one of Europe's top ten tourist traps......but that's the city not the surrounds.

Enjoy Dingle and the Blaskets.....some of the best days my wife and family have ever had. (If you get a chance the Skellig Ring and south side of the ROK to Sneem is incredible as well !)

We are staying near Killarney N.P. For three nights next month. We plan to drive the Beara peninsula, which is remoter and wilder than both the Dingle peninsula and the ROK.
Also doing Muckross House, Gap of Dunloe etc. There is plenty to do in that area to fill several days!

We loved Killarney National Park. We rented bikes just outside the park and biked the park to Muckross house and farm. It was gorgeous.

Although Killarney and the NP have a lot to offer, it's the getting there and back that poses the problem. As a day trip from Dingle you'd be driving right into teeth of the morning rush as the tour buses start their daily circuit, then would have the same problem as you depart in the afternoon.
I agree that the better use of your limited time, rather than being stalled in traffic and searching for parking in and around Killarney, would be to explore the northern part of the ROK - especially the Gap of Dunloe and the Skellig Ring. The Skellig Center at Portmagee is worth a stop too. One of the (many) nice things about the Skellig Ring is that the tour buses don't go out there which makes for a very pleasant day trip. There's a lot to see and do: the Kerry Cliffs, the Skellig Chocolate factory, the ruins of an old monastic settlement near the village of Ballinskelligs, and there's a nice beach close by that's a great spot for a picnic or just to stretch your legs for a bit. A good turnaround point is the village of Waterville - another pleasant little town that invites strolling along its seaside promenade.
A day trip to Killarney from Dingle is doable, just know what you'll be getting yourself into before you set out for the day.

Thanks for your feedback. I think we will spend our extra time just kicking around Dingle.

Well, if you're looking for an off the beaten path day trip on the peninsula you could head up over Conor pass to the village of Aughacasla and then drive out to Glenteenasig (Little Glen of Waterfalls) Forest Park. There are a couple of pretty boardwalk hikes around one of the lakes (about 1.3 miles for the loop) and lots of possibilities for a picnic lunch.
On your way back stop at the South Pole Inn in the village of Annascaul. The pub was established back in the 1910's by Tom Crean, who was one of the crewmen on the Shackleton Antarctic Expedition in around 1914. Don't know whether the place is still run by his descendants but it has a lot of old photos and artifacts about Crean and his career in the Royal Navy - basically it's a little museum that doubles as a pub (or vice versa I guess), and they do pour a terrific pint of Guinness. Could also stop by Inch beach just up the road.

Robert, thank you for your suggestion. It sounds very interesting. I will definitely look into it.

There is now a ferry service between Dingle and Valentia Island......So it is easy to pop over.... Valentia is really nice...the tetrapod tracks, the great view from Bray Head.....and if you like a fairly easy 2 hour hike the Bray Head Loop with insane views and a Napoleonic watchtower. Plus you're next to the Skellig Ring, the gorgeous Kerry Cliffs, an eco tour of Skellig Michael, the Glen etc, Skeliig Chocolates, the Abby ruins and McCarthys Castle and some good food in Portmagee. Another great option.