Toberaspagher Fort, as it was recorded in the 1840s, takes its name from a spring well that once sat at the eastern extremity of the enclosure, described at the time as "a handsome spring well... out of which issues a little stream of pure spring." The well is gone. The name remains.

The site sits within a rath, a type of circular earthen enclosure used in early medieval Ireland, typically associated with farmsteads or settlement. The Ordnance Survey Name Books of the 1840s captured the place-name and its explanation at a moment when such wells were still a working part of the landscape. The Irish word "tobar" means well, and it anchors the fort's identity entirely to that water source. By the time anyone thought to look closely at the ground again, the landowner could only confirm that a well or spring had indeed been here until relatively recently, with no visible remains left to mark it.