Bell holes are described as vertical, cylindrical, dissolutional cave ceiling voids. Quantitative analysis of bell holes in San Salvador, Bahamas; Isla de Mona, Puerto Rico; Kentucky; and New York permit bell hole morphology to be contrasted in various geological settings and speleogenetic regimes. Mean bell hole height is 36 cm with a width of 34 cm and cross-sectional area of776 cm 2. Bell holes have elliptical openings, conical to cylindrical profiles, strong vertical development, and sometimes are associated with bell pits. Bell hole width remains constant between the study localities, but height varies. Several processes have been proposed to explain bell hole development: bat activity, condensation corrosion, phreatic degassing, vadose percolation, and phreatic convection cells. The vadose mechanisms seem unreasonable in light of bell hole morphology and setting. Thus, a phreatic process functioning in a laminar or slow-moving turbulent flow regime most likely accounts for bell hole formation.