DVD. Secrets Of Lost Empires The civilizations of the ancient world left behind awe-inspiring examples of their engineering genius. Yet few clues remain to tell us just how, with limited technology, they achieved their extraordinary feats. To uncover the secrets of such Herculean labors, NOVA sent teams of experts to five archeological sites. The challenges? To actually test their building hypotheses-using traditional techniques. Pyramid takes us to the shadow of the Great Pyramid of Giza, where Egyptologist Mark Lehner, stonemason Roger Hopkins (of This Old House), and a team of Egyptian workers face the daunting task of building an 18-foot stone pyramid in three weeks. Obelisk again sends Lehner and Hopkins to the land of the pharaohs, this time to show how a colossal obelisk could have been quarried, chiseled, shipped up the Nile, and erected on a base in front of a temple-using only stones, ropes, logs, dirt, and some monumental human effort. Colosseum travels to the famous Roman amphitheater, where the blood-thirsty audience was once shielded by a gigantic canopy. Historian Rainer Graefe has come up with a controversial explanation of how, but will it win out over a more accepted concept? Stonehengevisits one of the most mysterious places on earth, erected by early Britons some 4,500 years ago. Archeologist Julian Richards, engineer Mark Whitby, the intrepid Roger Hopkins, and a band of volunteers give it their best-to move, raise, and cap a Stonehenge-like structure, armed only with Stone Age tools. Inca profiles the magnificent, earthquake-enduring Incan citadels high in the Peruvian Andes, all built without benefit of the wheel, iron tools, draft animals, or mortar. A team of experts chip away at some theories- and local villagers create a breathtaking, 100-foot suspension bridge using nothing but grass.