Walking tour of Cobh includes history on the Cunard Line (See the building where Bridget and David departed Ireland) , White Star Line and The Old Cemetery,; to name a few.
If you can only do one overnight trip, I HIGHLY recommend a trip around the Beara. The roads are too narrow for tour buses so you get a quiet scenic drive with some lovely small towns. A few of our favorite small towns on the Beara are Glengarriff and Bantry.

Leave the urban buzz behind and wonder at the stunning Irish countryside. Admire the Cliffs of Moher and gaze out to the Atlantic Ocean, before heading through traditional villages on your way back to the city.
Upon arrival at the majestic Cliffs of Moher, admire the impressive views of the natural landmark where Ireland gives way to the Atlantic Ocean. The sharp cliffs, climbing to more than 700 feet (214 m) at their peak, offer inspiring views of the ocean.
Enjoy lunch in the village of Doolin, famous for its traditional food and Irish music, before driving along the scenic route through the Burren and Wild Atlantic Way. Get a glimpse of Corcomroe Abbey, a 13th century monastery and head to Village of Kinvara on Galway Bay for photo stop, before returning to Dublin.
Play the course of the 2014 Irish Open.