A small stone chamber sitting in a grazed Kildare field is, according to at least one tradition, the point from which the River Boyne begins its journey across Ireland. That claim, noted by Fitzgerald in 1917, may raise an eyebrow or two among those who associate the Boyne's headwaters with County Meath, but it speaks to the kind of local reverence that has gathered around this spring for generations. The well itself is modest in its dimensions, a pool roughly sixty centimetres across, enclosed within a mortared stone structure barely two metres long and less than two metres wide. A small arched doorway with red-brick jambs gives entry, and the vaulted interior, tall enough to stand in, creates an atmosphere of deliberate enclosure that sets it apart from the unadorned field around it.

The ritual attached to this place is specific and long-standing. It has been recorded as a site frequented on Trinity Sunday, the eighth Sunday after Easter, when pilgrims come to drink the water, which is considered lucky. This kind of gathering is known in Ireland as a Pattern, a term derived from "patron" and referring to a devotional assembly held on a saint's or feast day at a sacred site, often involving prayer, circumambulation of the well, and the drinking or collecting of its water. The practice here was noted by the Ordnance Survey Letters in the early nineteenth century and was still being observed as an active tradition according to research published in the late 1970s, suggesting a continuity that has outlasted many comparable sites elsewhere in the country.

The structure shows its age. The vaulted roof has been described as unstable, and the ground around the well is heavily poached by livestock, which has churned the surrounding pasture. The well lies on level ground, roughly thirty metres west of a small southward-flowing stream. Anyone visiting should approach with care given the condition of the roof, and should expect a working agricultural setting rather than a maintained heritage site.