[3] Poem X, stanza 2, composed c. 1349 by Giolla na Naomh Ó hUiginn, which states, Innte a-tá an tiobra as dtig Sionann/sruth as uaisle i n-Inis Fháil (In it is the well whence comes the Shannon, noblest stream in Inis Fáil).

[2][4] Their progress was hampered by submerged tree branches, equipment problems and poor visibility in the dark brown water.

After widening the slit and continuing downwards past a loose cobblestone slope, Kozłowski discovered an unstable chamber.

[2] The highest point in the catchment is a spring at Tiltinbane on the western end of the Cuilcagh mountain ridge; this sources an unnamed stream which itself feeds into Shannon Cave.

Further sinks that source the pot include Pollboy and, through Shannon Cave, Pollahune in County Cavan and Polltullyard and Tullyrrakeeragh in Fermanagh.