In his famed poem, Mending Wall, the American poet, Robert Frost, chided the rock wall that he and his neighbor would mend each spring, replacing fallen rocks. “He is all pine and I am apple orchard. My apple trees will never get across and eat the cones under his pines, I tell him. He only says, ‘Good fences make good neighbors.’
You can see the Great Wall of China from outer space. It is an astonishing piece of work.
Begun in the fifth century B.C. and added to by later dynasties, it succeeded in defending China from invasions by northern tribes. In 1600, it helped the Ming dynasty defend against the Manchu, but when the gates at Shanhaiguan were opened in 1644 by a dissident Ming border general, the Manchus quickly seized Beijing and that was the end of the Ming dynasty.
