The Great Wall's engineering marvel

Today, I visited one of the wonders of the world - the Great Wall of China. This ancient architectural masterpiece was started over 2,000 years ago, during the Warring States period, and expanded in the Ming dynasty. Its purpose was to protect the country from the invading northern tribes. The scale and length of the wall is truly impressive. It's estimated that the total length is over 13,000 miles! The wall has been built in difficult mountainous terrain that is prone to strong winds and earthquakes. Its construction involved the use of local materials, such as rammed earth, brick, and stone. The wall's design accounts for the pressure from supporting elements of the wall and gives structural rigidity to stand up against any weather. I found it interesting how the designers made subtle alterations to lessen any damage. To my analytical mind, it shows how much thought and attention to detail was put into its creation.