That last detail sits quietly alongside the more familiar mechanics of Catholic folk devotion, lending the place an atmosphere that is harder to categorise than a straightforward holy well or wayside shrine.

On 8 July each year, people would make "rounds" at the lake, a penitential practice in which participants walk a prescribed circuit, often barefoot, pausing to pray at particular points. Rosary beads were left hanging on the branches of the willow trees nearby, a gesture common to sacred sites across Ireland where the leaving of an object marks a completed act of devotion or a petition made. What distinguishes Derrylough is the local belief that the lake was twinned with Lough Mackeenlaun in Derryrush, County Kerry, on the northern side of the Beara Peninsula. Lough Mackeenlaun is a well-documented penitential station in its own right, and the perceived spiritual kinship between the two bodies of water across the Cork and Kerry border suggests that people understood the landscape of the Beara as something shared and connected, rather than divided by county lines. The floating islands, meanwhile, sit somewhere between geological curiosity and local legend. Masses of peat and vegetation do occasionally detach and drift in shallow lakes, so the observation may have a physical basis, though it is the kind of detail that tends to accumulate meaning over time regardless of its origins.