What was once a pair of symmetrical formal gardens flanking a country house in County Kildare has been reduced, by ploughing, to almost nothing visible at ground level. The first edition Ordnance Survey six-inch map of 1838 shows them clearly: two rectangular, formally laid-out enclosures with internal pathways and divisions, one sitting to the north-east of Rathcoffey House and measuring roughly 90 metres east to west by 80 metres north to south, the other a slightly smaller mirror image to the south-west, approximately 70 by 60 metres. By the time an aerial photograph was taken in the 1970s, both had been reduced to low earthworks. Today, extensive tillage has removed even those subtle traces.

The gardens would have been a fairly conventional feature of a demesne landscape of that period, formal geometry close to the house giving way to more naturalistic grounds beyond. What makes Rathcoffey rather more interesting is what lies about 450 metres to the south: an elongated pond or lake, roughly 180 metres long and 30 metres wide, recorded on the same 1838 map and positioned on lower ground in a way that suggests it may have been designed to close a view from the house, functioning as a terminal feature in a planned vista. The pond is now dry, and locally it goes by the name the 'decoy', a word that in an Irish estate context often referred to a managed water body used to attract wildfowl. Whatever its original purpose, the dried-out hollow turned out to contain something far older than any garden design. In the 1890s and again in the 1950s, it yielded several skulls and antlers of giant Irish deer, the species Megaloceros giganteus, an animal that stood around two metres at the shoulder and carried antlers spanning up to three and a half metres, extinct for roughly ten thousand years. The finds were noted in the Journal of the Kildare Archaeological Society in 1945.