Photo: Jorge Orta, Studio Orta
Jorge Orta is a Paris-based Argentine artist noted for his work with PAE light cannons, which he uses to project images onto mountains or large buildings. The image above was projected onto the Evry Cathedral in France in 1996 and is called "Cardinal Cross." Other images at the link include projections onto Machu Picchu, inside the Aso volcano in Japan, and the Cathedral at Chartres.
http://www.studio-orta.com/artwork_fiche.php?fk=&fs=9&fm=0&fd=0&of=0 via Gizmodo