The Walled Garden is situated on rising ground in the Pleasure Grounds. The garden is 1.9 acres in extent, delimited by walls of stone and brick. The garden was built in the mid 18th Century and partly re-modelled in the mid 19th century with the addition of circular brick turrets at each of the corners. The gardens were entered from the Pleasure Grounds by gates on the west, south and east sides, those on the east and west were notably ornamental, and were almost certainly by the famous Dublin Ironmaster, Richard Turner.
The gates were described in the 1860’s as being ‘beautifully bronze and richly coloured of elegant design’. Internally, the garden was sub-divided by paths at right angles and by paths running around the perimeter in classic kitchen garden fashion. At the centre where the diagonal paths met, there was a rose trellis. The main path down the centre was lined by a dramatic herbaceous border. Frequently, these borders were backed by espalier apple and pear trees which not only shielded the vegetables to the rear from view but also helped to provide the garden and border with additional shelter from wind. Vegetables grown in the garden included broccoli, turnips, savoys, and carrots.
Inside the walled garden the north east and north west walls are lined with brick. This allowed tender plants such as figs to be grown as brick walls retain heat very efficiently. Other plants included Jasmines, Magnolias, Wisterias, Solanums, Smilaxes, Passifloras, Myrtles, Ceanothus,Spiraeas and Escallonias. The north west wall was the main fruit growing wall as it faced south east. Most of its length was lined with glasshouses, the bases of some of which survive still. The glasshouses which were once heated by stoves, were filled with plants, chiefly for decoration and cut flowers. These included Celosias, Begonias and Cyprepediums (orchids); fruits included vines, peaches and pineapples.