A big, round, 4,000-year-old stone building discovered on a Cretan hilltop is puzzling archaeologists and threatening to disrupt a major airport project on the Greek tourist island. A big, round, 4,000-year-old stone building discovered on a Cretan hilltop is puzzling archaeologists and threatening to disrupt a major airport project on the Greek tourist island. Archaeology Phys.org – latest science and technology news stories