According to some estimates there were more than 3,000 holy wells in Ireland, many of which are still marked on the Ordnance Survey maps. It is believed that the tradition of visiting holy wells may have survived from pagan times and can be traced as a Christian practice from the seventh century. There is also a theory that the tradition of placing offerings at wells may have been influenced by Roman Britain. There are many such holy wells in the Tallaght area and visiting holy wells was part of the social life of the area.
St Colmcille’s Well on the Ballycullen Road near Orlagh College was one of the most frequented wells of the area. It contains a statue of Colmcille within a stone gable-fronted niche that was added in the early 1900s. Pilgrimages took place to the well during the threat of conscription in 1918, according to Paddy Healy. A nearby tree had religious medals nailed into the bark as offerings from those visiting the well and also rags tied to the tree. These were known as clootie trees. The tree fell in the 1960’s.
St Kevin’s Well at Kilnamanagh is all that remains of the monastery known as Cill na Manach na nEscrach where St. Kevin is said to have studied under St. Éanna, St. Lochan and St. Eoghan. He then founded his own monastery at Glendalough.
In Tallaght village a well at the old Glebe House, close to the church, was covered in and used as a domestic supply. When the Rector of the Glebe House was holding an auction in 1791 the old people of the area attended in order to drink the water from the well.
Some of the other wells in the area include one on the slopes of Crooksling, where there is a well called Tobar na Cluar used for the relief of earache. Nearby in Boherboy townland there is a well dedicated to St Patrick. St Anne’s well in Glenasmole is a stone lined well in the base of the sacred tree of the same name.
The people of the Tallaght hills would also have travelled to the holy well at Lacken, Co Wicklow which was famous for its cures. It was covered by the water of the Blessington reservoir but is occasionally exposed during periods of drought when people flock to it once more, as many as 3,000 people visited the well in 1978 when it was revealed.