The Spring and Autumn and Warring States periods, though marked by disunity and civil strife, witnessed an unprecedented era of cultural prosperity--the "golden age" ( ) of China. The atmosphere of reform and new ideas was attributed to the struggle for survival among warring regional lords who competed in building strong and loyal armies and in increasing economic production to ensure a broader base for tax collection. To effect these economic, military, and cultural developments, the regional lords needed ever-increasing numbers of skilled, literate officials and teachers, the recruitment of whom was based on merit. Also during this time, commerce was stimulated through the introduction of coinage and technological improvements. Iron came into general use, making possible not only the forging of weapons of war but also the manufacture of farm implements. Public works on a grand scale--such as flood control, irrigation projects, and canal digging--were executed. Enormous walls were built around cities and along the broad stretches of the northern frontier.http://www-chaos.umd.edu/history/ancient2.html
The Great Wall is the world's longest human-made structure, stretching over approximately 6,400 km (4,000 miles) from Shanhai Pass in the east to Lop Nur in the west, along an arc that roughly delineates the southern edge of Inner Mongolia. It is also the largest human-made structure ever built in terms of surface area and mass.Just like a gigantic dragon, the Great Wall winds up and down across deserts, grasslands, mountains and plateaus, stretching approximately 6,700 kilometers (4,163 miles ) from east to west of China. With a history of more than 2000 years, some of the sections of the great wall are now in ruins or even entirely disappeared. However, it is still one of the most appealing attractions all around the world owing to its architectural grandeur and historical significance.
History of the wall: Excitement abounds in the origin, vicissitude and nature of the great wall of the Qin, Han, and Ming dynasties.
The Great Wall was originally built in the Spring, Autumn, and Warring States Periods as a defensive fortification by the three states: Yan, Zhao and Qin. The Great Wall went through constant extensions and repairs in later dynasties. In fact, it began as independent walls for different states when it was first built, and did not become the "Great" wall until the Qin Dynasty. Emperor Qin Shihuang succeeded in his effort to have the walls joined together to fend off the invasions from the Huns in the north after the unification of China. Since then, the Great Wall has served as a monument of the Chinese nation throughout history. A visit to the Great Wall is like a tour through the history backwards.