The Great Wall is a masterpiece of construction of ancient China that has also high symbolic value. The stone and earthen fortifications in northern China were built originally to protect the northern borders of the Chinese Empire against intrusions by various nomadic groups. The wall stretches for 8,800km and spans 17 Chinese provinces. Several walls have been built since the 5th century BC that are referred to collectively as the Great Wall, which has been rebuilt and maintained from the 5th