The holy well at Cooldurragha in North Cork sits within or immediately beside a rath, the type of circular earthwork enclosure, typically dating from the early medieval period, that once served as a farmstead or defended residence. That a sacred water source should occupy the same ground as a rath is not unusual in Ireland, where the boundaries between pre-Christian and Christian significance were often blurred rather than redrawn. What is unusual here is the name, and the small discrepancy in where exactly the well was understood to sit.

The well appears on the 1842 Ordnance Survey six-inch map positioned inside the east-south-east bank of the rath. By the time the 1937 edition was produced, it is shown in the fosse, the defensive ditch that runs around the outer edge of the bank, and it is given a name: Tubber an eeling. Tubber, from the Irish tobar, simply means well. A memorandum dated 20 December 1931 notes that local people referred to the entire fort by this name, calling it Tober aneeling, suggesting the well had become so associated with the place that it effectively named it. What eeling means in this context is less immediately clear; it may be a phonetic rendering of a personal name or an epithet in Irish, though the notes do not supply a translation or a patron saint.