Tafoni, Zion National Park, 2014.

Tafoni also goes by the names honeycomb weathering, fretting, stonelace and stone lattice. These small, smooth-edged openings can be found in granular rock like sandstone, granite and sandy-limestone with rounded entrances and smooth concave walls. You are most-likely to find this geologic feature in arid or semi-arid deserts on a vertical or inclined surface away from surface runoff. Accelerated, focused weathering of pockets of rock with slightly-hardened bands between the pockets results in this intricate, lacy structure.