Janet Jarman In the fall of 2003, a heavy rainstorm swept through the ruins of Teotihuacán, the pyramid-studded, pre-Aztec metropolis 30 miles northeast of present-day Mexico City. Dig sites ...

The same type of radar used by the pyramid researchers, Synthetic Aperture Radar or SAR, was coupled with artificial intelligence to discover a 5,000-year-old city beneath the desert in Dubai.