Centuries ago, they performed miraculously technical brain surgery, built modern irrigation canals, made agricultural discoveries still used by modern man, and were master builders. The stone village of Machu Picchu, 9,000 feet above sea level, stands as the awe-inspiring monument to their genius. How did they get the stones up the mountain to construct this architectural marvel? They were the Incas, a wondrous people who once ruled half of South America before falling to the Spanish Conquistadors.