A crescent Venus as seen in ultraviolet light by the Hubble Space Telescope. JPL. Back when Earth was very young, our home world was steadily pummeled by large solar system debris. While Earth withstood the barrage of hits like a prizefighter that wouldn't fall down, one blow nearly destroyed the world.
10 Legends and Stories of the Great Wall of China (1). The majestic Great Wall was built with wisdom, dedication, blood, sweat and tears. As one of the Eight Wonders in the world, the Great Wall of China has become the symbol of the Chinese nation and its culture.
Later dynasties repaired and rebuilt the Great Wall of China along the northern border to continue to deter those northern tribes from raiding. Because the walls were built of mud, gravel, and wood, repairs were often necessary. The wall that is seen today was mainly built by the Ming Dynasty in the 1400's B.C. Most of the artisans from this later time used stronger elements in the construction such as bricks and stone. Better materials made for a much more permanent structure.