It once sat at the bottom of a steep west-facing slope, roughly thirty metres from a nearby graveyard, in ground that has since been quarried away. No physical trace of the well survives.

The confusion over its dedication goes back at least to John O'Donovan, the nineteenth-century scholar and topographer who, writing around 1840, recorded that a pattern, the traditional Irish gathering of prayer and communal celebration held at a holy well on a saint's feast day, had taken place here, but doubted that Saint Ambrose was the genuine object of veneration. His scepticism seems well placed. Ambrose was a Roman aristocrat of the fourth century who became bishop of Milan in AD 374, celebrated for his fierce opposition to Arianism, the theological position that Christ was subordinate to God the Father. He was a significant figure in early Christianity, but his connection to a rural well in County Wexford is, to say the least, tenuous. A medieval document from 1408 lends weight to O'Donovan's doubts: in it, a Thomas Fourneys, rector of Rathmore in County Meath, is described simultaneously as chaplain of "the Blessed Mary of [Am]brosetoun, diocese of Ferns." That single record suggests the church and well were likely dedicated not to Ambrose at all, but to the Blessed Virgin Mary. The townland name, it seems, may have gradually reshaped local memory of what was once a Marian site into something else entirely.