In Belarado they have dozens of these in the sidewalks. Each one is for someone who was important in the history of the Camino. Martin Sheen was the only one we recognized.
From the web: The Paseo del Ánimo in Belorado, Spain, is a 2008 public art project on the Camino de Santiago featuring bronze tiles with handprints, footprints, and signatures of notable figures who supported the pilgrimage.
We just read there was one for Emilio Estevez as well, but we missed seeing that one. Of course Martin Sheen and Emilio Estevez were there about then making the movie The Way.