Teotihuacán home of the Mexican Pyramids, the great Avenue of the Dead and the Temple of the Feathered Serpent it is a two thousand-year old urban wonder. Claimed by Aztecs as the City of the Gods, it was not until the turn of this century that archaeologists realized that the eight mile square city was not Aztec at all, but built by a much earlier civilization. Planned and mapped out according to the stars and built over a series of sacred caves, at its height, Teotihuacán was the seventh largest city of the ancient world. Its power and influence was felt throughout Mexico and as far away as the western jungles of the Mayan Empire. Despite its advanced civilization, however, Teotihuacán remains wrapped in silence; the Teotihuacános never developed a writing system they left neither stories nor statues behind. We know little of who they really were. Who were their kings, their priests? Why did they build the pyramids? Did they, like their Maya neighbors, practice human sacrifice? This program explores the recent excavations made by on-site archaeologists as they look for clues hidden in the city's sacred caves and in the abstract images of its many murals clues that will someday reveal the secrets and stories of this once mighty empire.