13,170 miles in length 13,170 miles in length 13,170 miles in length 13,170 miles in length 13,170 miles in length Great Wall of China Longer Than Previously Reported Great Wall of China 13,170 miles in length 13,170 miles in length 13,170 miles in length 13,170 miles in length 13,170 miles in length Earlier in July, ABC News