Great Wall Beijing, China

China's Great Wall stretches east-west for more than 5000 kilometers. Its origins can be traced to the 7th Century BCE, when independent kingdoms constructed separate walls to keep out marauding nomads. China's first emperor linked many of these during the Qin Dynasty (221-207 BCE). It was renovated several times in later centuries. Built along the rolling ridges of steep mountains, it offers spectacular, even awe-inspiring views, and is surely one of humankind's greatest architectural achievements. The Great Wall is best enjoyed in sections, some of the more popualr visiting sites include Badaling , Mutianyu , Simatai and Huanghuacheng. Badaling is by far the most visited section and each has its own charms. At any given section of the wall, be prepared to wear sturdy shoes and dress for inclimate weather.