Opposite end of the country to me so I don't know it very well but I have had few cycling trips. Definitely worth doing IMO.
Go out around Ardfield and Galley Head and also places like Timoleague and Roscabery, Glandore and Union Hall or on to Baltimore, Barleycove strand and Mizen head depending on the sort of distances you're happy to ride in a day. A stunning piece of coastline.