Although Patrick won the battle, he may not have won the war. Over the centuries, a unique Celtic Christianity developed, influenced by the Desert Father and Egyptian Coptic Christianity, that embraced isolated, ascetic monastic life such as found on Skellig Michael, a craggy, isolated island 10 km off the southwest shore of Ireland.
Celtic Christianity encouraged far-flung missionary activities and maintained a close relationship with the natural world. Irish Christianity lasted at least until the twelfth century, when Norman England and Rome-administered Catholicism conquered the Emerald Isle. It was never completely extinguished, and in recent decades it has experienced a renascence.
The Hill of Slane has other claims to fame than Patrick’s Paschal flame. The so-called motte on the western side, inaccessible and hidden in the trees, is said to be the remains of the 1170s fortification of Richard le Flemyng of Flanders. It is probably instead the ancient burial mound of the Fir Bolg king SlÃ¡ine, who legend claims is buried there.
A ruined Franciscan church and college from the sixteenth century still survive on the hill. St Erc’s original foundation and his remains may lie to the south of the present church or possibly in the ruined â€œmortuary houseâ€ in the graveyard. Tradition says that the two gable ends, with large upright rectangle stone end-blocks, are the remains of Erc’s shrine. These standing stones may be the remains of a megalithic construction that was Christianized as was the Hill of Slane. As late as the twentieth century, the shrine was visited as part of local burial rites.
The Hill of Slane is intervisible with Newgrange and Knowth, about 5 kms to the east. On a clear day you can see Drogheda, the Irish Sea, and the Wicklow Mountains to the south.
Source Powerful Places in Ireland