I know I’ve been posting a lot of classic architectures lately, but they are amazingly constructed as well. I will post some modern architectures soon. The Great Wall of China is built along the northern border of China to protect the Chinese Empire against intrusions by various nomadic groups. The Wall was built during the 7th century BC, and was made with stones, bricks, tamped earth, and other materials. The wall is approximately 3,107 miles, which makes it the longest structure in the entire world!