The Great Wall's construction is unique in that it is primarily made of local materials wherever it is found. This is why the sections in the mountain regions tend to last longer than others. The second distinguishing feature is that the core of the Great Wall was made of compacted soil. Once this core is finished then several layers of finishing materials are applied over it. Finally, the wall was fortified for military purposes; towers for lookout and communication proposes were added, walkways and garrison posts for defense were also added. This created a strong and stable wall that was resistant to the weather and to attack by the enemy.

The First of the walls were started around 680 BC and the last of the walls were made in 1644. The Great Wall spanned many dynasties and countless emperors. This means that the Great wall is the longest lasting construction project in human history.