Overview: Nine years ago, French architect Jean-Pierre Houdin became obsessed by the centuries-old mystery of how the Great Pyramid was built. For ten hours a day, he labored at his computer to create exquisitely detailed 3-D models of the interior of the Great Pyramid. After five years of effort, the images rotating on his computer screen provided evidence of an astonishing secret. Corkscrewing up the inside of the Great Pyramid is a mile-long ramp, unseen for 4,500 years. The pyramid was built from the inside. This revelation casts a fresh light on the minds that conceived one of the wonders of the ancient world.