EGYPT: There has long been speculation about how the Great Pyramid’s 2.3 million stone blocks, each weighing two tons, were transported to the site. Pollen analysis from desert cores taken near the pyramid revealed that at the time of its construction 4,600 years ago, the area may have been covered with marshy plants commonly found along riverbanks. The finding implies that a defunct arm of the Nile River, which is now located 4 miles away, once flowed much closer. This could have greatly facilitated the delivery of building materials.