Just off the shores of Lake Titicaca, Peru, rests a peculiar wonder that defies explanation. In a region known by the Peruvian Indians as “The City of the Gods,” measuring in a perfect, twenty-three-foot square, is the Puerta de Haya Marca—the “Gate of the Gods”—an absolutely bizarre stamp embedded in the side of a flat, natural rock formation on the border of Bolivia. Inside the square, at the bottom center, is another recessed impression within the rock (standing just under six feet high), which, from a distance, resembles a kind of keyhole.