The Great Wall of China is one of the eight wonders of the world, and for good reason. The massive wall constructed from dirt, stone, wood, and brick spans an impressive 13,171 miles. The construction project was started in 220 B.C. and lasted over 2,000 years, finally finishing in 1879. Even though people come from all over the world to see the Great Wall, to some, the wall is just a wall. And what do walls do? They get in the way.