The rockery was developed at the end of the 1880s, and is constructed from stone quarried at nearby Finglas.|
Farrer described the Glasnevin rock garden as one of the finest examples of what he termed the "Devil's Lapful":
"The plan is simplicity itself. Take a hundred or a thousand cartloads of bare square-faced boulders. You next drop them about absolutely anyhow: and you then plant things amongst them. The chaotic hideousness of the result is something to be remembered with shudders ever after" (R.Farrer, My Rock Garden).