@CNN: Archeologists have spent centuries wondering how the towering pyramids of Giza were constructed thousands of years ago. Now, the discovery of a sophisticated ramp system has put them one step closer to solving the mystery. https://t.co/xlSru00T20 https://t.co/2zFGObRtmf

@CNN: Archeologists have spent centuries wondering how the towering pyramids of Giza were constructed thousands of years ago. Now, the discovery of a sophisticated ramp system has put them one step closer to solving the mystery. https://t.co/xlSru00T20 https://t.co/2zFGObRtmf