La Cruz de San Gregorio Curiosity · Pozo Alcón, Sierra de Cazorla, Jaén Image of Pozo Alcón, not of the place itself. Local tradition attributes to two Jesuits the carving of the letters IHS and a cross on a stone during a hailstorm on 9 May, the origin of the San Gregorio procession. Photo: Andrew.brown.garcia (CC0) What to see and do in Pozo Alcón