The Great Wall of China is the largest man-made feature on the planet. It is actually several different walls which were constructed throughout a period of 1,875 years. The total length of all of the sections measures over 2,950km. A great wall indeed. It is listed as one of the Man-made wonders of the World. As far back as the 4th Century BC large walls separated kingdoms within the region that now makes up China.
Many cities were surrounded by large walls which acted as the primary defense against all to common invasions. Southeast Asia was comprised of over a dozen different independent States which were constantly at war with each other and which caused there borders to change quite frequently. By early 3rd Century BC the number of States had been reduced and the few remaining had become quite powerful.