A hollow on a sheer face, produced by localized weathering, mainly through granular disintegration (pl. tafoni). Canopy-shaped, overhanging cave roofs are typical. In semi-humid to semi-arid regions, tafoni weathering is among the most effective weathering processes operating on surfaces of plutonic rocks such as granite (Brandmeier et al. (2011) ESPL 36, 6, 839). Data gathered by Roqué et al. (2013) Geomorph. 196, 94 support a subterranean origin of some tafoni. Norwick and Dexter (2002) ESPL 27 find that the rate of tafoni enlargement decreases over tens of thousands of years. Hejl (2005) Geomorph. 64, 1–2 describes a prehistoric wall painting which displays stages of tafoni development.