This is another option, but the roads are not as smooth and the signs are not well posted!
Take the N11 North to the Arklow South exit. This brings you into Arklow town. Turn left and follow the road down into town. When you get to the roundabout, go straight through it. This road turns into the R747. Take the R747 to the R752. You will pass the Woodenbridge Hotel, Avoca and then Meeting of the Waters. Keep going straight and you will come into Rathdrum. Follow the road down the hill. There will be a petrol station on your left. At the bottom of the hill, before you cross the river, turn left at the Ivy Leaf Apartments and Hidden Valley Park.