In the townland of Dromgower in County Kerry, there is a holy well that no one can find. It appears on the 1916 Ordnance Survey map under the name 'Purtaheen', a small cartographic acknowledgement that something was once there, yet by the time researchers came looking, no physical trace remained. The 1842 OS map does not mark it at all, which places the well in an awkward historical middle ground, acknowledged in one century's survey and untraceable in the next.

The sole written reference to the well comes from John O'Donovan, the nineteenth-century scholar and place-name expert who contributed extensively to the Ordnance Survey Name Books, a series of field notebooks compiled in the 1830s as part of the first large-scale mapping of Ireland. O'Donovan noted the existence of a holy well in this townland but recorded no name for it. Holy wells were a fixture of Irish devotional life, typically small springs or pools associated with a local saint or curative tradition, often marked by a pattern day and various ritual practices. Without a name, this one slips further from reach. 'Purtaheen', the name that does eventually appear on the 1916 map, may be a diminutive form derived from the Irish, though its precise meaning in this context is unclear. Whether the name came from local usage or was applied by map-makers working from incomplete information is unknown.

What remains is a kind of negative space: a feature recorded in words, later plotted on a map, and now gone without explanation. It may have been filled in, built over, or simply dried up over the course of the intervening decades. In North Kerry, as elsewhere, the landscape has been substantially altered by drainage schemes and agricultural improvement, and many features that once held local significance quietly disappeared with them.