The Great Wall of China: Built to Last

The Great Wall of China, located between southern Mongolia and northern China, is the longest wall ever built by humans. Constructed over 2000 years, it served as a defense against Mongolian invasions. The wall stretches 13,170.7 miles, with an average width of 21.3 feet and height of 20 to 23 feet. Built using various materials, including stone, wood, and brick, it features 2500 watchtowers. Despite its military origins, the wall also facilitated trade and peaceful interactions. Today, it attracts millions of visitors annually and is recognized as a World Heritage Site.

How many people visit the Great Wall each year according to the Chinese government?

In what year was the Great Wall declared a World Heritage Site?