Guess what? The Great Wall of China is the largest thing that people have ever built! It's super long, stretching about 2,700 kilometers from east to west. But when we count all the different parts, it's even longer—around 6,400 kilometers!
A long time ago, before China became one big country, there were many smaller states. These states built walls to keep out tribes from the north who wanted to take their land. Then, in 221 BC, a powerful emperor named Qin Shi Huang came along. He decided to connect all these walls and make them into one giant wall.
China was always worried about those northern tribes, so they made the wall even taller and stronger during the Han and Ming dynasties. The wall was built to be 6–9 meters high, so it was hard for people to climb over it. They also built watchtowers every 100 meters so they could keep an eye out for enemies. The wall was made using different materials like dried earth bricks, fired bricks, and stones. Even though they worked really hard on it, the wall didn't fully protect the people as they hoped.