Planet Earth is the home of some spectacular relics from bygone era, constructions that seem to defy the technological capabilities of their time either because they are too big, too heavy, or too complex. In Giza - the most famous of Egypt's pyramids rise from the desert built more than 4500 years ago, the pyramids at Giza are monumental tombs where queens and Pharaohs were buried. The stone crafting Rapa Nui; but a leading theory suggests their...