The Great Wall of China is the largest construction ever built by man. It was built over 2000 years ago. The construction started in 5th Century BC. It was built originally to protect the northern borders of the China from intrusions. Since then, several walls have been built. Collection of all such walls is referred to as The Great Wall, which has been rebuilt and maintained from the 5th century BC through the 16th century. One of the most famous is the wall built between 220–206 BC. This structure has been built by generations. According to some historians, around 300,000 soldiers and 500,000 people participated in the construction. The beautiful wall took the life of many people and many people are buried under the wall. It costs the lives of more than 1 million people. It stretches approximately 6,400 km (4,000 miles). The wall is 25 feet tall and from 15 to 30 feet wide.