About the amazing construction

2. About the amazing construction The Great Wall of China, one of the greatest wonders of the world, was listed as a World Heritage by UNESCO in 1987. Just like a gigantic dragon, the Great Wall winds up and down across deserts, grasslands, mountains and plateaus, stretching approximately 8,851.8 kilometers (5,500 miles) from east to west of China. With a history of more than 2000 years, some of the sections are now in ruins or have disappeared. However, it is still one of the most appealing attractions all around the world owing to its architectural grandeur and historical significance.

3. How it was built? The Great Wall of China is a series of fortifications made of stone, brick, tamped earth, wood, and other materials, generally built along an east-to-west line across the historical northern borders of China in part to protect the Chinese Empire or its prototypical states against intrusions by various nomadic groups or military incursions by various warlike peoples or forces. Several walls had already been begun to be built beginning around the 7th century BC;these, later joined together and made bigger, stronger, and unified are now collectively referred to as the Great Wall Especially famous is the wall built between 220–206 BC by the first Emperor of China, Qin Shi Huang. Little of that wall remains. Since then, the Great Wall has on and off been rebuilt, maintained, enhanced; the majority of the existing wall was reconstructed during the Ming Dynasty.

4. Visible from the moon?! • One of the earliest known references to this myth appears in a letter written in 1754 by the English antiquary William Stukeley. Stukeley wrote that, "This mighty wall of four score miles in length (Hadrian's Wall) is only exceeded by the Chinese Wall, which makes a considerable figure upon the terrestrial globe, and may be discerned at the moon." The claim was also mentioned by Henry Norman in 1895 where he states "besides its age it enjoys the reputation of being the only work of human hands on the globe visible from the moon." The issue of "canals" on Mars was prominent in the late 19th century and may have led to the belief that long, thin objects were visible from space.[33] The claim that the Great Wall is visible also appears in 1932's Ripley's Believe it or Not strip[34] and in Richard Halliburton's 1938 book Second Book of Marvels. • The claim the Great Wall is visible has been debunked many times, but is still ingrained in popular culture.The wall is a maximum 9.1 m (30 ft) wide, and is about the same color as the soil surrounding it. Based on the optics of resolving power (distance versus the width of the iris: a few millimeters for the human eye, meters for large telescopes) only an object of reasonable contrast to its surroundings which is 70 mi (110 km) or more in diameter (1 arc-minute) would be visible to the unaided eye from the moon, whose average distance from Earth is 384,393 km (238,851 mi). The apparent width of the Great Wall from the moon is the same as that of a human hair viewed from 2 miles (3.2 km) away. To see the wall from the moon would require spatial resolution 17,000 times better than normal (20/20) vision. Unsurprisingly, no lunar astronaut has ever claimed to have seen the Great Wall from the moon.

5. The Great Wall of China was included as a World Heritage Site on the basis of Cultural Criteria I, II, III, IV and VI in 1987 • Criterion I. The Great Wall of the Ming is, not only because of the ambitious character of the undertaking but also the perfection of its construction, an absolute masterpiece. The only work built by human hands on this planet that can be seen from the moon, the Wall constitutes, on the vast scale of a continent, a perfect example of architecture integrated into the landscape. • Criterion II. During the Chunqiu period, the Chinese imposed their models of construction and organization of space in building the defense works along the northern frontier. The spread of Sinicism was accentuated by the population transfers necessitated by the Great Wall. • Criterion III.  That the great walls bear exceptional testimony to the civilizations of ancient China is illustrated as much by the tamped-earth sections of fortifications dating from the Western Han that are conserved in the Gansu province as by the admirable and universally acclaimed masonry of the Ming period. • Criterion IV. This complex and diachronic cultural property is an outstanding and unique example of a military architectural ensemble which served a single strategic purpose for 2000 years, but whose construction history illustrates successive advances in defense techniques and adaptation to changing political contexts. • Criterion VI.  The Great Wall has an incomparable symbolic significance in the history of China. Its purpose was to protect China from outside aggression, but also to preserve its culture from the customs of foreign barbarians. Because its construction implied suffering, it is one of the essential references in Chinese literature, being found in works like the "Soldier's Ballad" of Tch'en Lin (c. 200 A.D.) or the poems of Tu Fu (712-770) and the popular novels of the Ming period.

6. Interesting Facts • During its construction, the Great Wall was called “the longest cemetery on earth” because so many people died building it. Reportedly, it cost the lives of more than one million people. • The most visited section of the Great Wall is in Badaling, close to Beijing, which was built during the Ming Dynasty. It was the first section of the wall to open to tourists in 1957. It is where Nixon visited and was the finish site of a cycling course in the 2008 Summer Olympics. • According to legend, a helpful dragon traced out the course of the Great Wall for the workforce. The builders subsequently followed the tracks of the dragon. • A popular legend about the Great Wall is the story of Meng Jiang Nu, a wife of a farmer who was forced to work on the wall during the Qin Dynasty. When she heard her husband had died while working the wall, she wept until the wall collapsed, revealing his bones so she could bury them. • Uranus, or Tianwang, who was the personification of Heaven, is often portrayed on the reliefs found at strategic points and passes on the Great Wall. • Voltaire (1694-1778) discussed the Great Wall several times, but he remained undecided what the real point was. In one piece, he thought the Egyptian pyramids were “childish” compared to the Wall, which was a “great work.” In another place, he calls the Wall a “monument to fear.”