The site, known variously as Tobar Ceann Moir, Tobar Cinn Mhóir, and Tobar Canvore, translates roughly as the Well of the Great Head or Spring, though a rival tradition insists the name belongs not to the water itself but to the man who found it. The well springs from a chasm cut into the hillside of Slieve Reagh, a feature that earlier observers noted as evidently artificial, and the stream it produces, called Sruth Ceann Moir, flows northward before joining the Morning Star river.

Writing in 1896, Dowd recorded the local legend in some detail. A great Druid, he explains, ordered his disciple Canvore to fetch a magic spear, which the Druid then threw high into the air. Canvore was told to dig wherever it landed. He did so, and a copious stream of water came up from the ground. When the disciple asked what reward he would receive for his efforts, he was told simply that his name would always be associated with the place. This version of the story was also noted by Dr Joyce, who offered a slightly different reading of the same tradition. The site appears in the 1928 edition of the Ordnance Survey Name Books as Tobar Cinn Mhóir, and the folklorist Caoimhín Ó Danachair cross-referenced it with Keating's History of Ireland, suggesting its reputation extended well beyond local memory. The well sits in the townland of Glenbrohane, near the boundary of Emly Grennan, roughly three miles to the south of Knocklong.

The well lies on the roadside, which makes it relatively easy to locate, though the surrounding landscape of Slieve Reagh, where the Munster army was said to have been posted according to older sources, gives the spot a quietly layered quality. The artificial chasm in the hillside from which the spring emerges is the detail most worth looking for; it distinguishes this from a purely natural source and hints at deliberate shaping of the site at some point in the past. The stream itself is a useful guide once you are nearby, flowing away in a short northerly course toward the Morning Star.