When a bunch of engineers, scholars, and craftsmen come together to figure out how Egypt's massive obelisks were erected, there's bound to be some disagreement. By today's standards, the feat seems impossible- in creating these mighty monoliths to the gods, the pharaohs' teams had nothing to work with but stones, ropes, logs, and dirt. Using such simple tools- and superhuman patience- ancient workers carved from solid granite, one of the hardest rocks to work, a stupendous shaft weighing some 400 tons. Then they chiseled, without benefit of a chisel, exquisitely detailed hieroglyphs along its side. After transporting it miles down the Nile to its base in front of a temple, their crowing achievement was setting this colossal object upright without a fracture line in sight. How did they do it? NOVA puts Egyptologist Mark Lehner, stonemason Roger Hopkins (of This Old House), and other experts to the challenge, testing out various theories involving a temporary sandbox, a giant counterweight, a gradually built-up ramp, a slowly sliding sled, levers, pulleys, ropes- and the giddy enthusiasm of hundreds of local helpers who lend their monumental efforts to the task.