New Digs Decoding Mexico's "Pyramids of Fire" John Roach for National Geographic News October 21, 2005On TV: Watch National Geographic Explorer: Pyramids of Fire, Sunday, October 23 at 8 p.m. ET/PT on the National Geographic Channel. Using picks, shovels, and high-tech forensic sleuthing, scientists are beginning to cobble together the grisly ancient history and fiery demise of Teotihuacán, the first major metropolis of the Americas. The size of Shakespeare's London, Teotihuacán was built by an unknown people almost 2,000 years ago. The site sits about 25 miles (40 kilometers) north of present-day Mexico City. Temples, palaces, and some of the...