There is an iron gate at the top and, at the bottom, a whitewashed chamber with a separate iron door set into the eastern wall. The structure sits roughly 1.8 metres below street level, which gives the place an odd intimacy; you descend out of the ordinary town and arrive somewhere quieter and older, or at least somewhere that feels that way. Folklore collected from local schoolchildren recorded that three holes in the wall around the well could grant a wish if you pressed your fingers into them, and that the imprint of a saint's foot could be found on one of the steps going down.

The well is traditionally associated with St Colmcille, also known as Columba or Columb, the sixth-century monk born at Gartan in Donegal who founded monasteries at Derry and, most famously, on the island of Iona. A plaque erected by the local historical society inside the gate states that in 590 AD Colmcille blessed the well and in doing so gave Swords its name, 'Sord Cholmcille', meaning clear or pure water. The Schools' Folklore Collection, gathered from Swords pupils in the 1930s, preserves several versions of how the well came to exist: in one, the saint stepped from the church to a spot where water bubbled up; in another, he leapt directly from the monastery; in a third, he was building near the Round Tower when a single great stride towards the Main Street caused the spring to rise where his foot landed. All versions agree on the footprint. The well was formerly visited for the cure of sore eyes, and earlier traditions recorded that Colmcille used the water to cure lepers. When the folklorist Caoimhín Ó Danachair visited in 1958, the well opening appeared dry and filled with stones, with no signs of active devotion. By 1975, when Henry A. Wheeler recorded it for the Sites and Monuments Record, water was again flowing through a shallow basin, though its source was not the original chamber but a point beside it.

The well is located off Well Road in Swords Village, within sight of St Columba's church, and is marked on all editions of the Ordnance Survey Ireland historic maps as St Columb's Well. A water pump stands immediately to the north. The structure itself is probably not medieval in its current form, as Wheeler noted in 1975 that it was impossible to date but likely not very old, though the spring it encloses and the traditions attached to it are considerably older than any stonework. The whitewashed walls and the enclosed steps down from street level make it easy to identify once you are on Well Road and looking for it.