The well at Ballon in County Carlow appears on the Ordnance Survey six-inch map of 1839 with a note recording it as "now dry", meaning that by the time the first systematic mapping of Ireland was under way, the water had already gone. Holy wells were, and in many places remain, sites of popular devotion, typically associated with a local saint and visited for the curative or spiritual properties attributed to their water. Without the water, the ritual purpose largely dissolves, and such sites tend to fade from active memory faster than almost any other category of early sacred place.

The reference to the well survives in the Journal of the Kildare Archaeological Society from 1933, which suggests it was noted by a researcher interested in the area's older landscape features, even at a point when the well had been out of use for at least a century. Ballon itself sits in a part of Carlow with a layered early Christian and medieval presence, and the existence of a holy well there fits a recognisable pattern of localised sacred topography, where springs, trees, and particular stones accumulated devotional significance over long periods. That this one was dry by 1839 places its active life somewhere earlier, though the sources do not record when it ceased to flow or what, if anything, it was once believed to cure.