Penitential snow is a phenomenon associated with the high mountains of the subtropical and tropical dry zones of the Old and New Worlds. Snow cover that has formed during the wet season is subject to selective melting processes during sunny summer and autumn weather; these are governed by irregularities on the original snow surface and sculpt out closely spaced yet completely isolated firn spikes, which resemble a procession of figures in white penitential robes (penitentes). The photograph was taken at an altitude of 4,900 metres on the Huaitiquina Pass, which leads from Salta (Argentina) to San Pedro de Atacama (Chile). - Book: Picture 8 - Chile - 1975