<P> The North African traveler Ibn Battuta, who also visited China during the Yuan dynasty ca . 1346, had heard about China's Great Wall, possibly before he had arrived in China . He wrote that the wall is "sixty days' travel" from Zeitun (modern Quanzhou) in his travelogue Gift to Those Who Contemplate the Wonders of Cities and the Marvels of Travelling . He associated it with the legend of the wall mentioned in the Qur'an, which Dhul - Qarnayn (commonly associated with Alexander the Great) was said to have erected to protect people near the land of the rising sun from the savages of Gog and Magog . However, Ibn Battuta could find no one who had either seen it or knew of anyone who had seen it, suggesting that although there were remnants of the wall at that time, they weren't significant . </P> <P> Soon after Europeans reached Ming China by ship in the early 16th century, accounts of the Great Wall started to circulate in Europe, even though no European was to see it for another century . Possibly one of the earliest European descriptions of the wall and of its significance for the defense of the country against the "Tartars" (i.e. Mongols), may be the one contained in João de Barros's 1563 Asia . Other early accounts in Western sources include those of Gaspar da Cruz, Bento de Goes, Matteo Ricci, and Bishop Juan González de Mendoza . In 1559, in his work "A Treatise of China and the Adjoyning Regions," Gaspar da Cruz offers an early discussion of the Great Wall . Perhaps the first recorded instance of a European actually entering China via the Great Wall came in 1605, when the Portuguese Jesuit brother Bento de Góis reached the northwestern Jiayu Pass from India . Early European accounts were mostly modest and empirical, closely mirroring contemporary Chinese understanding of the Wall, although later they slid into hyperbole, including the erroneous but ubiquitous claim that the Ming Walls were the same ones that were built by the First Emperor in the 3rd century BC . </P> <P> When China opened its borders to foreign merchants and visitors after its defeat in the First and Second Opium Wars, the Great Wall became a main attraction for tourists . The travelogues of the later 19th century further enhanced the reputation and the mythology of the Great Wall, such that in the 20th century, a persistent misconception exists about the Great Wall of China being visible from the Moon or even Mars . </P> <P> Although a formal definition of what constitutes a "Great Wall" has not been agreed upon, making the full course of the Great Wall difficult to describe in its entirety, the course of the main Great Wall line following Ming constructions can be charted . </P>

Map of where the great wall of china is