Enjoyed my walk through the Fota Arboretum last Sunday. The house wasn’t open to the public at the time (it will re-open on April 1st) and neither were the walled gardens (they are open during working hours at present) but there is still plenty of interest in the stroll through the arboretum. There is no charge other than the three euro parking fee and you may also bring the dog, (provided he or she is on a lead).
When you enter from the dedicated car park, separate from the Wildlife parkings, you will pass a huge tree on your left. Pay your respects as you pass: this Monterey Cypress was planted here about 1847. Keep to the main path and soon you get a terrific view of the house. The entrance to the gardens and the trees is not signposted but is to the right of the house as you at it.
House info, including opening times: http://www.fotahouse.com/