Nobody knows exactly where. That is more or less the entirety of what can be said about its present condition, which makes it a curious case even by the standards of Irish souterrains, the narrow underground structures, typically dry-stone lined and roofed with flat slabs, that were built throughout early medieval Ireland and whose precise functions remain debated. They were likely used for cold storage, refuge, or both.

The structure came to light in 1906, when it was uncovered in the garden of a Nicholas Pomeroy. What was found was a flag-covered passage roughly three feet high and two feet wide, opening into a chamber of about eight feet square. These dimensions are modest but not unusual for a souterrain. The discovery was later recorded in 1937, but the precise spot within the garden was apparently not fixed with enough accuracy to allow anyone to relocate it since. There is no visible surface trace remaining, which is also common enough: many souterrains have been backfilled, collapsed inward, or simply grassed over without ceremony.