It still breaks through the ground today, sealed now under mass concrete, a small overflow trickling southward to a nearby stream. The well's Irish name, Tobar Rí an Domhnaigh, translates as the Well of the King of Sunday, a phrase that carries the kind of ecclesiastical weight common to early Irish sacred sites, where local springs were placed under the protection of a divine or saintly patron and visited on particular feast days. Locally it has always been known more simply as Sunday's Well, and the cure it was credited with was equally specific: headaches.

The well was already established enough to be marked by name on the 1841 edition of the Ordnance Survey six-inch map, which suggests it had been a recognised feature of the landscape for some time before the railway arrived. The townland it sits in, Ballymakegoge, lies in the parish of Ballynahaglish in the barony of Trughanacmy, a stretch of north Kerry running out toward the Fenit peninsula. When the Tralee-Fenit line was laid, the well was effectively consumed by the embankment. Caoimhín Ó Danachair, writing in 1958, noted that the well had disappeared in the making of the railway but that the spring continued to emerge beside the embankment. By the time the site was inspected in 1998, the railway itself was disused, the well reduced to a levelled area in rough pasture, with the concrete cover placed over the overflow by the railway builders still in place.

What remains is not much to look at, but the persistence of the spring is the point. The water found its own way out regardless of the concrete and the sleepers laid above it, and the local name held on just as stubbornly. Visitors would find the site on the southern side of the old Fenit railway embankment, with the small overflow channel still visible running toward the stream a couple of metres to the south.