A series of stone and earthen fortifications in China, built, rebuilt, and maintained between the 5th century BC and the 16th century to protect the northern borders of the Chinese Empire during the rule of successive dynasties.
a fortification 1,500 miles long built across northern China in the 3rd century BC
a fortification 1,500 miles long built across northern China in the 3rd century BC; is 1,500 miles long and averages 6 meters in width
a fortification 1,500 miles long built across northern China in the 3rd century BC; it averages 6 meters in width
