Great Wall of China

The Great Wall of China is the longest wall in the Real World, and, as its name implies, is located in China.

The Great Wall first appeared in an episode of The Adventures of Super Mario Bros. 3, "7 Continents for 7 Koopas". When Bowser tries to conquer the entire Real World, he puts Bully Koopa under control of Asia. Bully vandalizes the Great Wall of China by spraying graffiti all over it. Mario later steals Bully's wand, and turns the wall into a giant dragon, which then attacks and tries to eat Bully. Ironically, this could be seen as damaging the wall even more than Bully did. However, it is seen that later the wall and dragon both appeared at once (in the error screen (which happened due to the heroes' victories) and Bowser's defeat), though it is not explained how.

The Wall later appeared in the game Mario is Missing!, being vandalized by Koopas again. This time, a single stone from the Great Wall was stolen, and the Wall could not be visited until Luigi returned it. To do so, he had to defeat Koopa Troopas in Beijing and answer questions about the Great Wall to proof the stone's authenticity. When finally returning the brick, which was 23 centuries old according to a local scientist, he was rewarded $1225.

Pamphlet Information from Mario is Missing!
''One of the world's seven great wonders, the Great Wall is the only manmade object visible from outer space. The Chinese poetically call it 'Long Wall of Ten Thousand Li.' It is said that over 300,000 men labored for ten years to complete its 3,946 miles. Begun in fifth century BC, its purpose was to keep northern tribes from attacking southern states. The Wall was built wide enough to allow a team of five horses to run, side by side, along its top surface.''

Trivia

 * In Mario is Missing!, the pamphlet about the Great Wall of China (see above) says that the Wall is "the only manmade object visible from outer space", and a Beijing boy too claims that it is "the only manmade thing on earth an astronaut can see from space." This, however, is actually debatable.